Ask an OC Insider
There are no bath houses or similar places in OC where you can shower and change without getting a room for the night. There are open-air rinse of showers at the inlet and every few blocks along the boardwalk. There are public bath houses in the fee areas at Fenwick Island State Park and on Assateague.
You can also get a day camping pass at Castaways and use their shower and changing facilities. They are very nice!