Snakebites

I see that sucking venom out of a snakebite is discouraged (absolutely if you have an injury in your own mouth). This attempt at mitigation is ancient and very widespread, so at a wild guess it helps, despite some of the modern advice. (Sometimes hospitals can ID the snake from venom residue.)

Snake venom varies dramatically. In Africa some herbal treatments seem to be helpful, likewise in Bangladesh, among Amerindians, and so on.

Some of these work:

Ten studies reported statistically significant percentage protection (40-100%) of animals against venom-induced lethality compared with control groups that received no medicinal plant intervention. Sixteen studies reported significant effects (p ≤ 0.05) against venom-induced pathologies compared with the control group; these include hemolytic, histopathologic, necrotic, and anti-enzymatic effects. The plant family Fabaceae has the highest number of studies reporting its efficacy, followed by Annonaceae, Malvaceae, Combretaceae, Sterculiaceae, and Olacaceae. Some African medicinal plants are preclinically effective against venom-induced lethality, hematoxicity, and cytotoxicity. The evidence is extracted from three in vitro studies, nine in vivo studies, and five studies that combined both in vivo and in vitro models. The effective plants belong to the Fabaceae family, followed by Malvaceae, and Annonaceae.

Which is best for what snake might vary considerably. One wonders how this was decided on.

In Tribes of the Liberian Hinterland is a description of how the Snake Society was formed:

It is told that a hunter came upon two snakes fighting each other, and one was swallowing a leaf as an antidote for the bites of the other. The hunter then prepared medicine of the same kind of leaves, which he used with success in treating cases of snakebite. This incident led to the forming of the association.

On page 401:

A practice was found among the Loma similar to that described by practitioners of the snake cult in East Africa. A fine triturated black powder is prepared from the heads of poisonous snakes, charred, with certain herbs, in an iron pot. This contains the snake's venom, undoubtedly modified by the heating and certainly diluted by the charcoal with which it is mixed. Its action is further controlled by the herbs mixed into the compound. These are the same herbs which the leech uses in treating snake bite. This black powder is rubbed into tiny cuts in the skin of a person who wishes to be immunized against snake bite. The first immunizing dose is a small one, the next two are larger; a definite reaction is produced. The leech recognizes that this protection is temporary and that it must be repeated every two or three years. As the heads of several different varieties of snakes are used in the preparation of this powder, the immunizing effect is that of polyvalent vaccination.

This native practice even parallels our toxin-antitoxin immunizations, because he mixes with his toxin the remedy he would use in treating snake bite. The details of this treatment are guarded with great secrecy. Mr. Embree of the Methodist Mission in Monrovia once saw a boy bitten by a very poisonous snake. His comrades expected him to die. He asked them to wait while he went into the bush to get some medicine. They were surprised to see him return, as the medicine for that particular snake bite is known only bv certain big doctors. He admitted that he knew the medicine and begged the others not to tell anyone that he knew the secret, fearing the jealousy of those who were supposed to have a monopoly on the information.

Interesting. I don't know how fresh the plants have to be, and whether one could put together a "spectrum" treatment or whether it ought to be species-specific. As for immunity to snakebite: there are reports of it; species-specific. And reports of snake bite centers:

there are different dens in different cities wherein people who want to have snake bite are allowed to sit in chairs. The person in charge of snakes holds the snake near the head end of snake just distal to lip margin. Initially, he makes the snake to inject minimal bite in little toe or index finger for minimal envenomation, and then, he makes the snake to bite in lip or tongue of individuals according to their wish. The most commonly used snakes were krait, cobra, and green snake. Persons who were bitten, showed jerky movement and left the room within few minutes. From the reports provided orally, six persons lost their life due to such procedure. Many people who use such dens were from high socioeconomic status and well educated. Some of them were youth and college students.