I use this method and I really like it. Same caulk.
The only difference I do, is I'll water it down and put on a layer or two of the runny caulk first so it gets into the foam pores better, then finish it off with a layer of straight caulk. He also said you can't sand it, but once it cures and it's done shrinking, I sand it with 150 grit sand paper and get a really smooth finish and usually get it so you'd have to look really close to see a seam, if any at all. It takes longer, but sometimes worth it to get a nice smooth surface.