Mould on reusable make up remover pads?

[EL8888]

I have had some reusable make up remover pads for a while, l chuck them in the washing basket and them put them through the washing machine. Let them dry naturally and reuse. Recently l noticed what appears to be dark mottled stains but only on the back of them?! Is it damp and how do l sort it?

Could be mould, especially if they are sitting in a washing basket damp for a while. Do they smell? Could be makeup that is being sucked through the pads and isn’t washing off correctly.

I would bleach, wash then hang to dry in full sun. Should work on both makeup and mould.