For the lazy among us, you could also wrap a bit of electrical tape (or any tape) around one of the plugs in each pair. If you were to buy new ones, you can buy ones that are already in pairs with a solid plastic clip between them (although I don't know if those will fit every receiver and speaker binding post). I looked for clips that you could buy for yours, but I haven't found any, yet.
I agree about being more careful, though. I've used solid metal banana plugs for years without any issues.