Hey Folks, 

Ive been a long time lurker first time poster. I have a bit of a strange and shamfull question, I purchassed a set of ceramic stones a few months ago, and about 2 weeks after my last sharpening bonanza i noticed  a bit of mould growing on them. They seem stained and smell musty. Is there a proper way of cleaning them that wont effect the ceramic grit and kill the mould? 

Thanks for any and all help!