I had acne on my butt from last 3 years from last 8 month I was using benzyol per oxide 2.5%.and now my dermatologist had suggested me to use persol forte (which has percipated sulphur 5% and benxyol per oxide 10&) at day time and hydroquinone 4? at night before bed. My question is that is it safe to use benzyol per oxide with hydroquinone? If yes then would I need to wash the effected area again at night before applying hydroquinone.