OK, Washer and Dryer in your RV...Do you use them?

The "No washers" rules are sometimes related to limited sewage or water treatment capacities. I know of one park for instance, where the sites use the parks own well and RO treatment system, but the office and small laundromat are on a municipal water line that's not large enough to serve the whole park. A "No dryers" rule may be similarly related to limited park power capacity.