I hope my experience can help someone.
I have been suffering from severe butt acne for about 8 years. Tried benzoyl peroxide lotion, soaking in salt water, iodine, different acne creams, retinol - A, coconut oil, avoiding some foods ( milk, coffee, oil) - nothing worked.
Some time ago I was searching some new information about the subject and came across someone saying that usually people who sit a lot get butt acne. So I thought that maybe long time pressure on the butt causes ingrown hair. I have been really sitting a lot at work or when I am relaxing at home and laying on my back - there is still a lot of pressure on my butt. So I decided to avoid sitting and laying on my back even when sleeping. I lay on the sides and try not to sit at all or to sit for a very short time. Especially it's easy to do because I am not working at the moment. Have been doing this for about a week, and my butt is almost clear now - no new boils, old ones have dried out, no inflammation, just some dark spots that keep fading each day - I guess it will take some more time for them to fade as the boils were really deep. I am so happy that this nightmare is finishing!
Thanks, you experience is very helpful. As for removing boils on other parts of body, I'd recommend this instruction http://skintagsremoving.com/treatment-for-boil-on-neck-thigh-skin-vagina-back-face-and-under-arm/ , because all of them demand individual treatment.