Thats great. Using something for the unintended purpose. Especially if it inexpensive and available everywhere.

A while back on "This Old House" they visitied a crafts person in Hawaii who make custom decorative wood boxes.
For a finish, he used Gorilla Glue. He applied a string of it and then with a small piece of cloth wiped it on as a finish.

When its thin like that it just hardens into a polyurethane finish. (no foaming)