The bag is not big and is designed to hold a few items like underwear and pajamas. I understand the regular service is better (and more expensive) for more delicate items. I usually bring a little liquid detergent and wash something in the sink if it gets a stain on it.They don't have do it yourself laundry on any RCL ship. They do have a service, you send it off to get laundered. They usually have a special where the bag is $35 or so to get wash and fold. Not sure how big the bag really is, I have never used it myself.