When does a 20% salicylic acid peel get to work. And is it safe. (photo)

I bought a at home 20% salicylic and mandelic acid peel made by phytosil and I applied it yesterday day for 4 Mins but I didn't see and flaking or such so I did it again today but today I layered the peel over a time of 8 mins until the peel hadn't reached my dermis and frosting was visible so what can the possible side effects be I bought the peel for scars but I didn't need such a deep peel as most of my scars are light and superficial so what should I do now?