I once made a homemade window washer for my boat using the kits sold by JC Whitney for washer systems on Jeeps. Worked slick!
Nowadays I don't use one. Oh I do keep a bottle of that orange-colored window washer fluid on board that has 4-ounces of Salt-Away mixed in with it. But I routinely treat my windows with RainX and IMHO that works better than wipers could ever hope to.
I do have wipers - manual ones though, one above each window. They get more use with a morning mist than anytime else ...