Clay Plant Pots I Have Some Clay Planting Pots That Look Very Bad. I Want To Clean Them. Any Suggestions On How To Clean Them?

I have some clay planting pots that look very bad. I want to clean them. Any suggestions on how to clean them? - clay plant pots

I need to clean my clay pots and soil, I bought most of my plants, potting soil. It almost seems mold in clay pots. How can I clean it to make it look new.?
Please help!