I'm glad this topic is up as I will be dealing with this issue soon. I notice that mine will soon be falling off because it is wearing out. Stupid idea with no bearing.
I once saw a pic of a person who used the rear derailer as a spring loaded chain tensioner. That is my goal. On my old frame I was able to leave the tensioner off but now I find that I need it and must admit that it quietens things down and is worth using.