DON'T re-wet them. Brush them out DRY. If you re-wet them, even with conditioner, they'll just tighten up. If they're tight and you can't brush them out, do you know how to cut them to losen them so that you can brush them out? You pull the matted section out and hold it at "attention" and then put the sissors into the mat and cut in the direction of the hair.

I took some pics using a toy. I thought this was easier to understand than my horrible explanation.

The right way:


The wrong way:


Once you cut through them, brush them out. Just don't wet them again. It'll only to make much worse.