Here is a product that we probably can all use to get the old caulking off the exterior of our rigs...

https://www.amazon.com/gp/product/B0083RPVTM/ref=as_li_ss_tl?ie=UTF8&linkCode=sl1&tag=rvtravel04-20&linkId=e0cc0eac8beff73219dcf3fe31d31ff5

I actually keep a set of these on my work trucks. Probably the cheapest tools on the trucks and they work great. I use them quite often on tile and counter tops with adhesives dropped on them. Should work perfect on the roofs of our Rw's.

Steve