I've solved my hum problems. Yes, it's due in my case to dirty whatever, but my investigations revealed a lot of inconsistencies in traditional wiring practices on Strats.

All I want to do is find a way to ground the 5-way switch that I know for sure it's grounded. Narc, where do you attach your ground wire on your switch? Is there a coating that you have to sand off? Any prep? Since I've got my guitars all flayed at the moment, I thought I'd soup them up with shared knowledge from this thread.

Also, shielding DOES help my situation more than some, but not all the way. It's amazing how much hum it gets rid of. On my BL equipped guitars, I don't shield the PUP cavities; just the control cavities. It makes a HUGE difference. But, if you've got wiring problems in your walls, it won't go all the way. Radial's JDI is very good at taking the noise down all the way. The JDI Dual is even better because it offers a lot of options.