It does not matter that you are lucky to have not had all of your lenses crack on you from incorrect cleaning--you should avoid cleaning lenses with dishsoap, Windex, and other chemicals not specifically formulated to be gentle with the special coating you ordered. If you do not want to purchase a cleaner that is meant to be used on glasses, water works fine and use a 100% cotton cloth (not Kleenex.)
Lenscrafters also needs you to leave your glasses so they can make the lenses fit correctly, otherwise they cannot do anything to help you. It is entirely possible to purchase a spare pair without spending $400 at Lenscrafters, and it is entirely possible to purchase a nice inexpensive spare pair at another place while staying with Lenscrafters for a more fashion-conscious pair.
Lastly, Lenscrafters doesn't make the lenses themselves, but just as they work in tandem with companies like Ray-Ban and Prada, the same goes for lenses.