Has anyone used a 15% acid?

[NoTimeToDiet]

I’ve used 10% salicylic acid before and it’s ok, but has anyone used a 15% acid - salicylic or a different one? Is it a big step up? Thank you.

I can happily use 20% salicylic and 50% glycolic. I do however have rhino hide where my skin should be and weaker ones don't have much of an effect.

What's your skin like?

I can’t get on with glycolic so don’t use it but salicylic is fine. I tend to just use it on problem areas or just on single spots so not all over.