This won't fix a leaking washer, but there is a cheap and easy way to make any sprayer much more gentle.
Put a pressure regulator on your spigot, or on the hose near your wand or sprayer.
My city water is around 45 psi. When I used an $8, 30 PSI regulator, suddenly all my hand sprayers became gentle.
I'm not patient enough to use a 20 PSI regulator!
http://www.dripworks.com/produ...