D.M. Procida wrote:
I have some ceramic electrical insulation, that is a bit discoloured and
I would like to clean up.

It has a rough unglazed surface.

What do you suggest?

Thanks,

Daniele


It rather depends what the muck is.

Id try a strong solution of detergent first and a scrub, to remove any
oil/grease and surface stuff. Anything left will be absorbed into the
unglazed ceramic and more of a problem. May be bleach- it seems to work on
tile grout, my wife used it on the old tiled floor we had (it had wide
grout lines and seemed to stain).