Hi Iceaxe,
Hang in there, with a little more elbow grease it will get better. A couple of points:
When using toothpaste, you need to use the abrasive type stuff (typically white) as opposed to the gel type stuff. soft scrub is a very good alternative.
You can check to see if you have removed the silicone film which causes the problem by rubbing the glass with your finger (wet) If it squeaks - it's "squeaky" clean ;-). If you can't get it to squeak, you need to scrub it some more.
Another option is to torch it! Take a lighter and burn off the film - again until it's squeaky clean.
Not to overstate the obvious but even after all this you will still have to spit in your mask to keep it from fogging - but now spit will actually work!
- Robbert
www.SpearTrips.com