This is the best answer...I have done it many times when I was a tourist to the DR and traveled light with only a carry bag...Go with this suggestion.!
I know this thread is very old, but just in case there is a brand new lundromat called Wash Wash Boca Chica with excellent service and adfordable prices right on duarte street in boca chica and 40 meters from the beach. I leave my laundry basket with them head out to the beach and 3 hours later pick it up and head home. Thats what i call living in paradise !