All you need is a standard hose with VERY little pressure. Using a "power" washer is a good was to get water into the bearings and washing the grease away.
Just yesterday I came home from a ride on damp roads and path and my bike was covered with sand, dirt and grit. I "gently" washed the bike with a hose set at a very light setting and it removed all the dirt. I then cleaned the chain and drivetrain.
I quick wipe down with a microfiber cloth and it's perfectly clean.