@ ianr: Judging by its weight and look, and the fact that previous attempts to clean by boiling vinegar/lemon juice have left no mark on said pan, I believe it is made of steel. As for webcam...sorry...I am too much of a technophobe. However, I may take a picture and get hubby to plonk it on here. @ maxxi: You are the epitome of unswerving patience and endurance. I think, due to the fresh batch of bio powder solution, I have tonight been able to chisel away at yet more of the black stuff. Must be down to the last 10% now: it's getting exciting! Apologies for doubting you earlier. @ Loz: An interesting point. But are you saying then, that when I wash my red-wine/curry/tomato-sauce etc. stained white linen tablecloth at 95 degrees, that it is not the enzymes that are responsible for the removal of the stain(s)?