Step 5: Rinse off Your Screen
This is easiest to do with a lot of water pressure, but it's still possible to do without a hose attachment. Rub the screen with your hand to help the emulsion wash out. I've even gently rubbed with the scratchy side of a kitchen sponge. This can damage the screen a little bit, but it works pretty well. Don't scrub hard or you'll screw up your screen.
I find this part to be the hardest part. I always get a little frustrated that the emulsion doesn't wash off fast enough and worry that it'll harden while I'm in the process, especially on a sunny day. If your image was opaque enough you shouldn't have any troubles, though.