[TxMt] "Unbinding" a menu command in TextMate

Recently, I needed to unbind a TextMate menu command (Text:Reformat and Justify) so that I could use ^J for my own uses. Ale Munoz (the n is suppose to have a tilde above it but I don't know how to type that on a US keyboard, sorry) was kind enough to show me how to use the Mouse and Keyboard preferences panel to rebind that menu item to something else, which solves the immediate problem. However, this still begs the question; is there a way to _unbind_ that menu item, so that it has _no_ associated key binding? This can't be done using Ale's method.

Thanks, Ken