OK so I tried MSI afterburner so I thought I would update my results:
MSI Afterburner => Same as Smartdoctor. I could slow memory to 100 MHz under core, any slower and it would go back to 1000 MHz.
MSI Afterburner with edited .cfg => Actually sets the speed to whatever I set it too.I would recommend to anyone that is going to try this to first set a conservative profile (like your card's defaults) and bind a hotkey to it.
During the course of underclocking the memory, I found many settings that would completely corrupt the rendering of the MSI AB window and in some cases the whole screen. Hitting a hotkey to revert it automatically is a lot quicker then closing and reopening AB or rebooting.
If anyone is interested, I'm now running my 6850 @ 925 / 305 using default voltage (1.157 V). As a result, my GPU temps dropped about 4o
C even with the fan spinning ~500 RPM slower. Guess I can try to bump my core frequency up again now.
Thank you so much for the help.