....snip...

I clean the glass as follows...

1. Go to B&Q or similar and find one of those "paint scrapers" which takes
Stanley blades and uses the full width of the blade. Make sure you have a
couple of spare blades by the sound of the state of your cooker!

2. Scrape off the burnt on crap. Almost all of it should come off with
careful work, replacing the blade if it dulls. Remember to do both sides of
the glass

3. Finish off by cleaning the last few bits using Brillo pads.

You should be able to get the glass back to almost as new - especially if
you unscrew the know and possibly even hinges to make it simpler to get at
the bits which they obscure.

Finally, if you have a reasonably modern oven, it's probably self cleaning
on the interior. Do NOT put on caustic, instead open some windows, whack
the temp up to 250degC and let the heat and self-cleaning coating do the
rest. Worth doing this regularly to keep the crap down - even with tin foil
etc. there's always some splashing.

Paul DS.