Whilst in the vets the other week I was thumbing through a magazine as you do and in it were different ways of echo cleaning.
One of the things was to cut a lemon in half and go over shower doors, supposedly it would get rid of water marks and limescale. Well, today I have tried it and it seems to work and as a bonus the bathroom smells nice too. Must admit the shower doors where pretty bad as everything else I had tried previously didn't seem to shift it, so think it will need several goes, but I am up for it to see what the end result is.
Anyone else tried this?