Washing detail cloths....??? How to?

Is there any certain way I should wash my polishing cloths?? THey do get dirty. After I get a spot on them, I retire them. Now I have a pile of somewhat clean detail cloths...

How do I wash them? No Softener, I figured that much..... mild, or light detergent?

regular detergent with no fabric softner... thats what zaino says, at least