While I don't do it myself, I live on a large popular lake in CA and I see all sorts of motorhomes (Class A and C, slide-ins etc.) including some large diesel pushers towing boats. They all seem to launch at various ramps without any problems. It is a fresh water lake, so rust is not a problem--getting your tail into salt water would require a thorough hose-off ASAP.
2007 Winnebago 26P