Yeast rinsing is a waste of time. Pitch the correct amount (see mrmalty.com) and it will work great even with the hop flavored trub in it. Washing is done with phosphoric acid and only worthwhile for irreplaceable yeast.
For normal gravity beers (under 1.060) I just use a half cup of fresh slurry. If my slurry is a few weeks old I'd use twice that much. Pitching correct amount will add no noticeable color or flavors from the slurry. The dead yeast and trub fall to the bottom. The live yeast get busy multiplying. You end up with a nice heathy generation of yeast doing the work.
Everything is better with a beer.