In the long run, your tool eerrr.. ummm toy will last longer if you protect it with a condom. That, and you have to wonder, just what's taking place inside where all those soaked in fluids are going. microbially speaking of course.
We had a very nice jelly that some idiot tried to clean and make it lose that smell. The only effect was that the harsh cleaner I used on it made the jelly kinda gooey on the surface. It was a nice tool and one that the m-jo liked a whole lot.
Being the crafty sort, I grabbed one of those long ballons they sell for kids at the grocery store forced it open using a speculum kinda gadget and rolled it back over the jelly, using tiny admounts of clear rtv to ensure no slipping. I stopped rolling just past the knot. It saved the toy, and it actually cut down on a couple of the rougher ridges on it, and is still one of the m-jo's favorite.
The only thing worse than admitting infidelity is admitting that you've royally fucked up your partners favorite toy. IMHO.