I snake train my dogs myself.
Bandit got bitten in the face by a copperhead before he was old enough to train though.
Now, at least once a year, I catch non venomous snakes to refresh their training.
I guess I do alright at the snake training... You cannot run fast enough to touch either dog with a snake now.
They know the word "snake!" too. I associate it with their training.
If they are snooping in a thicket, I say "You better get out of there, there may be a snake in there!" and they promptly leave that area.