it is 100% bad for your skis and your bindings. if there is any small amount of dirt that gets on the turf (its impossible not to...) , or on the rail at all it will completely scratch up your bases from the friction, and if it gets in your bindings it can really fuck them up. Not to mention the fact that the soap will completely dry out your bases and make your skis super slow in the future, even if you try to wax them afterwards. if its a new pair of skis you really like i would definitely avoid using them on a summer setup.