Ok,
I'm scrubbing to link up fine points in the animation and lip syncing for an animated character.
I just thought there would be an easy way to clear all the files from the RAM that After Effects holds in there without having to restart the program to do it. The purge feature seems to only get rid of the visual renders, but in my case it is Audio that looks like it is still hogging.
I'll hunt down the answers to the questions in that FAQ.