I tried my fourth or fifth go at rinsing yeast a few weeks ago. On Tuesday, decanted off the remaining liquid on top, and dumped about just shy of 400mL of slurry into some wort to wake up the yeast for saturday's brew. Sat on a stir plate for 36 hrs, then into the fridge to crash cool.
Here's what it looks like this morning (sorry for the crappy phone pic):
As I understand it, the white ribbon is the yeast - could it be that this is ALL the yeast I actually have in there? However, the solids are well above 600mL now, so I'd think there was some growth. I'm concerned now that I don't have enough yeast from the looks of things.
I think I'm done with yeast rinsing - I'm obviously not very good at it, and I have never had a problem with pitching slurry and doing a dump at high krausen to take away the dead matter.