This video from GE demonstrates their official guidance on how to clean the between layers of oven door glass.
My oven has had versions drips and droops behind the outside glass for a long time, and I’d long simply assumed they were in some completely inaccessible sealed chamber.
But no: by taking the door off (easy), I was able to take a soapy cloth rubber-banded to the end of a framing square (official guidance: yard stick) and squooch it up inside to gently nudge off the stains (not as easy as the video suggests).
My result wasn’t perfect. But the glass is much-improved. And I neither broke the glass nor needed to disassemble anything beyond removing the door.