I believe that there is a test for the efficacy of materials at RF by
putting
a small quantity in a microwave oven, together with a mug of water to
see if they get hot (and are therefore unusable)

Anybody tried this and can report back?

(I shall cease cross-posting my homebrew posts also to uk.radio.amateur
because that only brings forth the Mongolian Hordes of children behind
the fence of the kindergarten school who wish to become the centre of
attention and make fools of themselves by shouting off personal abuse.

It is a sad reflection on the state of amateur radio in Brit, but there we
go)