I haven't done much cooking in my glass pots (Don't remember if these were  
really glass, but they were either clear amber, or clear brownish purple).   I 
only got them when my acupuncturist had me cooking up a mixture of Chinese  
herbs.  He said only a glass pan would do, if I remember correctly.  I  was 
directed to simmer the herbs for many hours, and therefore wouldn't  have 
expected 
anything to burn, but I remember I just couldn't get the residue  off the 
pots.  Of course scouring on glass with a steel scrubbing pad isn't  much fun.  
I 
have never used the pots again, but seem to remember I never  did get the 
caked-on or burned-on residue off.  
 
Of course, I'm not talking about the Corningware-type ceramic pans, or  those 
appearing to be clear glass, used to bake in the oven, or in the  microwave.  
These come clean easily by scrubbing with a stainless steel  scrub pad, or 
even the nylon back of a sponge (after soaking).  I was just  talking about 
those pots used on the stove top over a flame.
 
The handles on these glass pots also got very hot and were hard  to handle 
(similar to cast iron handles).
 
Hope this helps,
 
Jill