Hey Brew, I had the same questions too. I looked at several articles showing a trub line at the bottom and suspended yeast on top. The articles did mention that the solution was put in the fridge for 20 minutes to 1 hour before pouring off the suspended yeast and leaving the trub behind.
I made the mistake of putting the slurry in the fridge for over 24 hours. At that point, the suspended yeast settled on top of the trub, and I just had water and left over beer floating on top. If you pour off the liquid thinking it's suspended yeast, you probably won't have much.
The past couple of times I've washed yeast, I've done what the article says. put the slury in the fridge for 20+ minutes, allow trub to form on the bottom of the container but still having a slurry looking liquid on top. Pour the slurry looking liquid off into another jar for storage.
The articles also mention, when you go to make a starter from one of these jars, you pour off the liquid on top, and pitch the yeast at the bottom.
Make sense?