Great idea! Just be careful... you basically have to tie your knot big enough so that when you pull there is enough surface area to pull against the plug. Too small and it just may slip through the space it came through... make the knot too big and you may risk it getting stuck itself around a bend on the way back to the plug. Another caution... if you are pulling the knot , it may get wedged at the plug and get stuck itself. Sorry to be devils advocate... good luck!