For the surface of a MH (or any vehicle), soak towels in hot water and lay/hold them on the surface of the rig. Leave them there for about a minute and then just wipe the bugs off. Be aware if you have wax on the surface, hot towels will likely remove it.
In that case (waxed siding) fill a spray bottle 1/2 & 1/2 with peroxide and water. Spray on, leave about 5 minutes. The bugs will foam up as the peroxide works on the protein but it will NOT hurt your surface (I used it on my motorcycle). The bugs will wipe off quite well, but not as easily as they wet towel method. Best to use this on a regular basis. Decaying bugs can begin to affect the paint if left to rot there.
HTH