Hmmm... I'm confused now... there should be no 'hole' to where you could spray anything 'into' the throttle body..
Right here, into the inlet:
We may need to check the base of the EGR for vacuum leaks:
http://www.vortexbuicks-etc.com/tuning.htm
I did the "knuckle rap" test of the MAF while idling. If it's bad it's supposed to stall. I know this won't find 100% of bad MAF's, but he tried another one without change as well.