Love the Betty White saying....but shorted classic would be You Can't Fix Stupid even with Duct Tape...
How about. "I would like to help but I just can't fix stupid." or "You can't fix stupid, not even with duct tape"
I love Betty White's comments below from Jerrilyn. That is hilarious. Go with what you'd like Carolyn. Love Chris
I don't know what it should say, but I would go with jrob.