Perhaps Jimi will comment, I have seen vipers, esp young babies in videos tease fed, often tubed and it seems to work well, and I wonder if there is some operative tie in with bodily containment as with your method. It makes me wonder. Different, but, hmm
Al's video (and its successor, part 2) was pretty good. It was clear to me that those part 1 animals (neonate Java pit vipers,
T puniceus, a sexually dichromatic, semiarboreal taxon) had already been "trained" some. The second individual, the male, was more typical than the first (female) of what you would see early on, in a training regime. The first animal (one strike, one grab, eating right away) was more like what ! would hope to see after maybe 7-10 increasingly successful attempts. The male was more like what you'd see after 3-4 successful attempts. A first successful attempt usually involves lots of avoidance (flight, head-hiding, etc), then some defensive non-grasping (sometimes closed-mouth) strikes, then a few grasping strikes followed by dropping. Eventually, you may get a grasp, a long wait, and then - praise Jesus!!! - swallowing.
Some taxa - and some individuals - take better to side-stroking, others to tail-tapping, others to gentle dorsal pressing (maybe this is the operative tie-in you mentioned, Kelly?). Squams for example like the pressing. Few taxa, few individuals take well to face-slapping - often that just leads to panic & retreat. Approaching from below is often helpful. Putting the animal up on a perch - like the rim of that tub - can also work
well for arboreals. I don't like feeding on particle substrate, for ingestion concerns as well as simple interference. Clumps sticking to the pink, etc.
Some animals respond well to being removed from their enclosure, others do not. If not, and if they're "floor feeders" not perchers, I will often feed on a "dish" like a clean butter tub lid.
Finally, some taxa are just easier to train - they "get it" in 3 or 4 tries, not 30 or 40. Gimme a squam any day. White lips? Sheesh, PITA. (A big litter of stubborn white lips was what forced me to go collecting metamorph treefrogs! Which was the gateway drug to my current doctrine. More below.) In general I think arboreals are easier to tease-train, since their natural feeding modality is grab and hold, not stab and pull back. Although simply dropping the food item after eliciting a stabbing can be effective; I had a litter of ornate cantils once that were goofy like that. For whatever reason they wouldn't stab (or eat...) a live pink on their own, but if it "attacked" them they would stab it, and if they stabbed it they would eat it. We only had to play that game a month or so.
just put the snake and the pinky in small retail brown bags, upright and folded over at the top, and placed back in the enclosure
Yep, this can work great if the animal is one of those that responds OK to being handled before feeding, and doesn't require solicitation to bite. I've done this a million times if I've done it once.
Al's experience with the animal dropping the pink in response to him snapping the tub lid back on was standard fare in my experience. Until the animal is very well-trained I don't move once it's grasping the prey item.
Don't move an inch. Snapping a lid on a tub must generate something like a Richter 6 or 7 earthquake for a little snake. Unsettling. Duh - don't do that!
Honestly, in time I simply moved away from trying to get snakes to eat stuff they don't want to eat. Trust me, there's virtually always
something they want to eat. My husbandry not-so-secret is "determine what what they want, and just give it to them". You want a frog, baby? Who's your daddy? Here's a nice frog; plenty more where he came from. Gecko? Boom, done. Anole? Oh yeah, come to papa. To hell with parasite fears, just get some size on them. Once they're good eaters, switching them to mice is relatively easy with basic scent-transfer techniques. And once they're solid on mice, parasite purging is easy too, if you feel the need. I almost never do. You really cannot know the relief of
never staring down another all-night tease-feeding session for a litter of eyelash vipers, until you've suffered a year's worth of those. Hello froggies!
Tube feeding is more for assist-feeding. Now, some folks with little patience may run a little too fast to this solution, but I don't like them for feeding, they're for probing, giving injections, helping with any pieces of stuck shed, etc etc. For me, tubes mostly stay in storage, and for feeding usage are only for the rare hold-out who really and truly prefers to die, rather than eat anything whatsoever. At that point, it's no more "who's your loving daddy", and more like "alright then, you're my b*tch". In the tube you go, out come the long forceps.
With tubes I use solid food pieces - one at a time but several in a row - about a third the size of the snake's head. Every 3-4 days or so. It's pretty easy, and doesn't present the wrong-hole dangers of a liquid lunch. Which has its place, for true force-feeding. That's pretty rare for me - I don't buy or live-harvest nearly-dead animals, and I don't let them get to that point. I've never had a job caring for fresh imports. A few times, I have accepted something "interesting" (uncommon in the trade, or something I've never kept) that another person has almost - but not quite - killed and given up on. So my experience with the nearly-dead is quite limited. I'd say my success rate at getting those all the way up to "happy & healthy" is maybe 35-50%. Whereas with tube-assist feeding, it's closer to 100%.
My longest tube-feeding case (a "platinum" Hill Country
C ornatus, wild-caught as an adult) was about 18 months to start self-provisioning. During the active season I'd give it 3-4 rat pups at a time, restraining its forebody in a tube, with its face right at the opening and its back half free of the tube (and in my firm grip). Eventually - after its second captive brumation - that animal very reliably killed and ate small adult rats on its own. Shy animal, but glorious to behold due to its color, pattern, and head/body form. Kind of scary venom, very bloody kills.
Anyway, hope this was stimulating. Different strokes for different folks, and nobody's got the answers for everybody else. But if it works for you, keep it. If it doesn't, do something else. (This advice extends all the way to "how 'bout you just stop working with that taxon, dummy!" Some taxa exceed some keepers' grasp.)
cheers