Stripping Flip Stay-Dry/Synthetic Fiber Diapers?

BBunnyFan1

I bought some of the Stay Dry liners for the Flip system from a friend who only used a couple of them, but I have no idea what kind of detergent or anything that she used when she washed them.  (She did tell me that they had all been washed.)  I'm familiar with the routine to strip cotton diapers, but found some info online that said that fleece diapers (like in pockets) have to be washed by hand with a scrub brush on both sides of the fleece. I'm not sure how well that's going to work with the Flips since it's not just a single layer of fleece.  Anyone have experience with stripping non-cotton diapers?  Do I need to strip them before use or should a good washing or two with my diapers work?  TIA!!