i never try it before, but some dermatologist in here used phenol to treat acne scar , better than tca peel, but for me tca is strong enough for peel the skin
the place i go uses phenol in some of their deeper peels but they also mix it with other things so its not as strong. i would def try a tca peel first and go from there because you can get pretty good results from those alone.
ooh i wouldnt attempt 50% at home unless you are getting a diluted version of it somehow. when i get my peels they layer it so they do 4-5 layers which gives pretty good results. i would only have a professional do that though.