There are "Blue ROoms" parked all over the place, but if I were you, I'd either kiss ass with someone who had a trailer/motorhome with a bathroom, or pitch your tent close to one of the new cinder block restrooms - which are kept pretty clean and don't generally reek.
At the beach entrance there are restrooms with pay showers (I think they're a quarter), or there are really nice showers at the State Park RV campgrounds on Pier street (south beach entrance) - left side of the road about two blocks east of the gate. There's a car wash with hose bib fittings one block east of the north beach entrance (right side) so you can flush your ski on the way out. One of the best places to air your tires back up is the Union 76 station on the right side of Grand Avenue going east, about 4-5 blocks east of the car wash.
Have fun you guys...I'm bummin' I'm going to miss this.
LP