Using extra channel strips to control Aux Send and Aux Return?

[masterfader]

While working on my spare Mackie 8 bus, I discovered something interesting: One can use a channel strip to control aux send levels. (Controlling Aux Send 1) What I did was patch the aux send 1 output to the channel strip's tape return jack. On the strip, I turned the Aux Send 1 knob all the way down. And with all the assign buttons (including L/R Mix) off, the channel then controlled Aux Send 1. The output of Aux 1 is then that channel strip's Direct Out. You get EQ, Mute, fader volume control, and even access to other aux sends.

Has anyone else done something like this?