Flexseal ???

I used it on a friends old class C that was leaking badly in a rain storm. Water was dripping inside on his cab over bed after his Son in law tried to fix it with caulking. He bought 2 cans for $19.99 on TV. I wiped the area that I thought it was leaking and sprayed it on when the rain let up. When the rain started heavy again it no longer leaked. From my personal experience with it when the price drops to $5 a can I might pick it up just for such emergency repairs but will continue to maintain my roof with regular inspections and re caulking yearly.