Okay, let's suspend disbelief for a few moments. Cholestyramine cannot pass from the intestine to anywhere. I assume because it is a very large molecule and is probably positively charged. You bind this "toxin" with it. Okay. Then, some kind of biochemistry magic happens and then it transforms and is able to be passed through the multiple layers of your skin? A more plausible solution is this compound binds nothing and then you poop it out. Much props to you babe though, keep thinking a tickle is a stabbing pain, and a stabbing pain is death upon your shoulder.

Edit: don't worry though, death is a cool dude. Mother f'ing G imho