Just consider if you really want to care for that Brooks saddle by rubbing dressings and other stuff on it. I sweat profusely and my shorts and bibs are soaked at the end of a ride. Whether that's a problem for the saddle or not, I just couldn't get past the idea that I'd have a soggy, smelly stretched out piece of leather to put my butt on.

And then there is also rain water from the road being flung up on it's underside... unless you have fenders.