Prefolds originally used for burp cloths

Okay, so I’m only 11 weeks pregnant so I have a while to figure it out, but I can’t stop thinking about it lol. With my daughter I was gifted a ton of prefolds (no tags or anything so not sure what brand probably just some cheap ones) that I just used as burp cloths. They were definitely not washed to cloth diaper standards as I washed them however and with whatever.

I definitely am planning to cloth diaper baby #2 and want to try and use these prefolds since I already have a ton of them. How should I prep them? Would they need to be stripped since they weren’t washed with a cloth diaper approved wash routine? Bleached?