What concentration of TCA is typically used to treat porokeratosis on the arms and legs?

I learned this on RXderm and apparently, it is a miracle and I have no idea how it works and who figured it out: compound lovastatin and cholesterol cream. Available on Chemistry Rx and Skin Medicinals.

When I did peels, I used 20%. Nothing I had ever tried topically worked well.

Works well and is not very irritating.