well venomous snakes are kinda my specialty.
I've been a herpetologist specializing in them for 20 years
Think of the mechanics of a snakebite, a relatively thick liquid (venom) is injected into your body.
Sort of like if I were to inject liquid anywhere from 1/8" (pigmy rattlesnake) to 1.5" (big diamondback) deep into a wet sponge (if it hits soft tissue) or into a hose with the water running through it (hits an artery) and then give you your little snake sucker to try to get it back out.
See why they don't work?
and any sort of restriction - even a semi loose ace bandage is a BAD idea for anything other than a coral snake bite in the US.
There WILL be massive swelling with any other native species, so what goes on as loose can become a tourniquet really fast, virtually guaranteeing an eventual amputation. Even if you do keep it relatively loose, you are still concentrating the tissue destroying venom into a small area, greatly increasing the probability of amputation or disfigurement.
The vast majority of complications in the US from snakebite actually arise from treatment, not the bite.
Coral snakes are our sole members of the elapid family, they pack a very different venom from all of our other venomous snakes.
Their venom is closer to cobra venom, however its injected in such minute doses (IF you mange to get bit by one) that its rarely a potential for a fatality unless its in a small child or someone with compromised health.
I still have not been able to find a verifiable record of a coral snake fatality in the USA on a healthy adult. Treatment has killed a few though.
Elapid bites are where a constricting bandage is helpful.
That venom is less tissue destructive, so slowing it down is a good thing.
Rattlesnake/copperhead/cottonmouth bite first aid = keep the victim calm - thats the only place suction devices really help, so they at least feel like something is being done, and get them to a hospital ASAP for supportive treatment, and if needed, antivenom.
Thats why whenever I teach a class on snakebite, I always say the best first aid for a snakebite is a cell phone or a set of car keys, whicehver will get them to a hospital faster!
OK I'm done boring people with snakebite crap!