I towed my frame to the local car wash and used hot soapy water to clean it. Sandblasting leaves a lot of dirt and dust behind. When I got it home I used a leaf blower (electric 205mph wind) to dry it it out. The type of paint you are using will not care about the little suface rust that may form. I also did the same for the cab and doors. I have yet to see any sand fall out of anywhere nor did I have any sand in the paint.
Joe