DS has outgrown his newborn prefolds and I want to use them eventually for a second child, but I've started using them as burp cloths. I don't know if using them this way will ruin them some how. The main concern is should I just wash them with the rest of my laundry now (in my normal detergent instead of my diaper detergent). Will this ruin them, or perhaps just require me to prep them somehow before using them as diapers again. Thanks.