Before I traded my Winnebago Voyage without full body paint, I used this knife from Harbor Freight - Hobby Knife with Five Carving Blades
It is very flexible and can contour with the roof as well as the awning rail. I cut loose the two sides then just pulled the caulk bead out. It came out in several feet lenghts. Any residue I would go back over with the flexible blade. Then I cleaned with denatured alcohol. Seemed to work pretty well.
An air nozel to blow it out was helpful as well if you have access to a compressor.
Have not worked with the new unit as I have only had it a few weeks, so not sure if it will work with the full body paint.