After we did antibiotics, no one said anything about probiotics to me at the vet. I am most likely going to have to contact my vet this week about his problems and if it is necessary to bring him in.
About the tail painting, I won't be home on the weekdays and able to do that everyday. I am willing to try it, but it seems like a quick fix for an underlying problem and I'd hope to stop whatever is causing him to do it in the first place.
Also, he is starting his shed cycle, so he should be sleeping more and won't be attacking himself.