Mark is correct. Just use dish soap, wash and rinse really well. I take a towel and sqeeze the pad then finish up with air drying. If you put them in a plastric bag make sure they are completly dry. I put a damp white pad in a bag and it molded.
Great idea on marking the pads.
Oh I dont like to spin dry them with the PC. I heard you can if you dont go above 4 But I still dont do this.