I stripped shitty not quite anodising that PTS uses with nail polish remover, which is only 30% acetone, off a Magpul PTS Masada, that was less than a year old, given these haven't even been made in near 10 years, and you don't know the state of it under the paint, the risk is too high.
Hard anodising goes into the pores, normal does not. Hard Anodising is expensive, PTS cut corners and cheaped out, as you could lift it with light scuffing.