Keith: You have little to loose by trying it. I use this stuff for various things but not that application.
I also repair lots of small tires off of golf carts, 2 wheel garden trailers and the like With RTV. Usually if you screw out the valve stem, squish the remaining air out (tubeless) and push down you can use your finger and put a thin coating on the rim (the bead area) and on the tire. Air it up and the fix works great. I even fixed a leaky valve stem rubber section 5 years ago on a trailer and it has not leaked since.
If your air bags on the coach are totally collapses, then I think your proposed fix may not work. Seems to me the biggest problem is to get to where you could actually spray anything on 100% of the air bag due to obstructions.
Spray it one day and repeat the next. Who knows, you may be on to something great for those of us with older coaches.
Larry