Sorry, I suppose I should have elaborated on what I meant by 'dirty yeast.' I meant to say that the yeast slurry contains trub.
Indeed, I have read quite a bit about yeast rinsing, and I have also watched several videos about it. I'm about 90% sure that I'm doing it correct. However, I like S. cerevisiae's suggestion of simply decanting and storing the yeast in whatever beer remains after racking. The method eliminates many of the steps required in the yeast rinsing process. What's the best way to transfer the slurry from a fermenter to a bottling bucket? For lack of a better way, I have somewhat carefully been dumping the slurry into the bottling bucket as the liquid level is too low for an auto siphon.
To press the subject further, has anyone else tried to filter trub from yeast slurry? I have this grand scheme in my head that incorporates an inline #200 or smaller filter with one end attached to a hose connected to the spigot of the bottling bucket and the other end attached to another hose routed to a container or attached to a pump if gravity is not sufficient enough to pull the slurry through the filter. Will it work? I have no idea. I suppose I will get around to trying it someday.