Do you ever remove and dismantle your cassette to get the gunge out?

A spoke flange broke on my rear hub. While transferring this (10 month, 15000 km) cassette to the new wheel I found so much gunge, a mix of excess Squirt and whatever, in its nooks and crannies.

A good weight saving!

But I'm surprised that there's so much there, despite doing what I'd thought was enough cleaning over its life.