I agree. I used to always chip my holes as they would freeze, check them regularly so the ice didn't get too thick, and constantly mess with them. I purchased some other tip ups from my buddy and he gave me some homemade covers just as you explained. I think they were cut out of a gym mat or something of the sort. I kind of chuckled and tossed them to the side. One day I said what the heck, I'll try anything once. So i tried them out. And they worked great!! I did all my tip ups except one just to see the difference, and it was like night and day. I wont leave them at home again, they are a great idea, and as you were saying, they can be made for little to nothing.