I have used Corbin seats on a XR650L dual sport and have one on my FZ1 and now the Concours. The XR650L saw lots of rain, river crossings, mud, you name it and I never had a problem with the seat collecting to much water or foam distorting in any way. I really believe this is one of those things where the manufacture is just protecting their butt knowing the seat cover material they use are not waterproof and if soaked for to long can cause issues with thier proprietery foam. I don't even remember ever using any special conditioner on mine. Now I don't typically wash my bikes with a hose and water anyway (sometimes with the XR I would need to) but I wouldn't worry about doing so as long as you just dry the seat when your done.