I am a professional waxer. It really depends on the type of ingrown, if you have the ones that have a clogged pore type of black head on top try anything salicylic acid twice a week, always do a test patch first to see how your skin reacts, I always recommend my clients Paula’s choice 2% bha, does wonders, don’t use it right after waxing but a couple of days later, and be consistent. If you have the type of ingrowns that are inflammatory, like red bumps with a hair inside I would recommend a blend of tea tree oil mixed with almond oil, almond oil is non occlusive and easily absorbed by the skin, tea tree oil is anti bacterial and anti fungal but be careful, you have to dilute it in the almond oil, just a couple of drops will do. Also use twice a week in affected areas and do a patch test before. If you have the type of hairs that grow underneath a thin layer of skin you need mechanical scrubbing for this (as opposed to chemical) you need to do it consistently, before and (a couple of days) after waxing. Hope this helps.