Accepted Answer

Once that stuff gets baked on like that, I don't know of any solvents that will clean it off without etching the glass- harsh stuff. Your best bet, if you've gotten as much as you can with the razor blade is to rub it (gently at first, try not to use any more pressure than you need) with fine steel wool- grade 0 is probably good, 00 might be a little bit too fine for the job at first. Then as you get more of the fabric off, go to the next finer grade of steel wool until you have just glass left.
Now that I think about it a little more, you could also try some oven cleaner such as Easy-Off. That may do the job, even if you have to do it a couple of times- although keep in mind, that melted nylon is going to be tougher to clean than the stuff in the bottom of the oven.
I hope this helps!

Expert:	DFW SuperGeek
Pos. Feedback:	n/a
Accepts:
Answered:	1/3/2009

HVAC Technician

EPA certified Refrigerant recovery; 7 years experience working for hvac manufacturing co as a tech