Mugglenet has an article discussing this.
But I'm really not so sure that you need two people. Remember the "find the antidote" chapter, where Hermione goes to all the trouble of separating the potion ingredients, but Harry simply grabs a bezoar?
Seems to me that RAB would need only a bezoar, and not an accomplice. And Harry will need to start carrying a couple of those little guys around in his pocket.
If I am not mistaken, a bezoar does not work for all poisons. Plus, the issue isn't recovering from the potion, but having the strength to drink the whole thing in the first place. So I don't know if a bezoar will help.
Now here's a connection your post just suggested to me. A bezoar is a stone taken from the stomach of a goat. There is a throwaway comment (in Goblet of Fire, I think) about Dumbledore's brother Aberforth being prosecuted for practicing inappropriate charms on a goat, or something like that. Does anyone else remember? It's when Harry and his friends meet Dumbledore at Hagrid's cabin after the disclosure about Hagrid's mother. Do you think Aberforth (who isn't discussed much, after all) was some kind of bezoar/potions expert? He isn't very favorably portrayed... but his name does start with an "A," for those who think "R" and "A" are two people. Hmmmm. I've always wondered a bit about Aberforth.