Yes, you can use apple cider vinegar on your butt or wherever the warts are. I suggest dampening a cotton ball with the ACV and using a bandaid to hold it in place.
I also suggest you buy some castor oil, vitamin A and E (this can be in capsule form) and rubbing this on the warts three times a day for 5 days prior to applying the ACV. This will soften them and the warts will quickly get reduced once you apply the ACV.
It worked for me. It took about a two weeks but they are gone. I have more information on my hubpage.
Good luck and let me know if you have any more questions.