[arocks]

Forgive my naivete but can't this by achieved by using opaque teflon-coated insides? Teflon is already used as non-stick coating for pans. It might not lower friction as much as the video suggests but it should be better than glass.

[jules]

Too see that this doesn't work, pour ketchup in a teflon pan and try to get it out again.

[rmc]

I love simple scientific, experimental responses like that. Thanks :)