If you are doing this to keep drafts out, I think you should do just that. No reason it shouldnt work. I would use the Great Stuff for windows and doors... minimal expansion... Then mask off any areas nearby that you dont want the finish ruined, and don't touch the overflow until it has dried completely. Then just clean it up with a sharp knife. If your primary motivation is keeping critters out, it may or may not work. A few insects and rodents, if determined can dig or chew through it. And If you are hoping to keep moisture out, you would be better off with a good, quality silicone sealer, but you wont be able to paint it.