WEt and Forget is the biz for mold. AFA cleaning build up there is a product that the tub refinisher guys use to get things clean enough for the coating they use to stick. Not something that you can buy at the HD.
I looked for an MSDS on this stuff to see what's in it and didn't find anything. I'll tell you, it's badass. I had to apply to buy the stuff and they have a $350 min purchase to get started with their company. I've done a few sinks with their products.
So, if you can decipher what the stuff is, get it.