I've tried all the other remedies suggested here and found that they may not like some of the stuff I put on but they will persevere no matter what. The only way I have found to stop them from crawling out is to mix DIATOMACEOUS Earth with diaper rash cream (40% zinc) and use it like poly filla to plug their exit.
Please learn from my experience with these things. A caution would be when using any product on your butt also use it on your vag. When using creams and ointments on my butt, the little beasties decided to move into my vagina, then on to my urethra. If you think them being in your butt is bad, you really don't want to spread them anywhere else!
And, the icy hot balm (cream) burned the skin off my poor butt.