In my experience it only needs about 5-10 minutes in the dryer to reactivate. For maintenance, I spot clean until they're really dirty and toss them in the dryer for a few minutes every couple of weeks to maintain DWR.
Haven't ridden or swam in them yet. Just wore around a few times a week. They pilled for me in the crotch where the fabric rubs together when you walk and kinda starting in the seat. It's not something that's overly noticeable, just an annoyance when F Cloth already has it's shortcomings (wrinkles easily, lint/pet hair magnet, etc). I won't buy anything else made of it.