another great product that works is " Quick and Bright" its bio degrateable as well so its very safe for the enviorment.
works great on the rv's campers boats with getting all that and some of the other very stubborn stuff off. we use the tub of quick and bright and use it on a rag one way of getting under the class C's to clean under the cab area is to use a swifter and put your cloth of quick and bright on that and then rub that underneath works like a champ!!
Happy trips!