Ceramic Hob Cleaner and your shower doors

Like most households our shower doors have always got build up of water marks, because we live in Rotorua where there is always sulphur in the air, our windows and doors are worse than the average....I have tried all sorts of things from oven cleaner to vinegar, CLR and other strong cleaners to no avail. I happened to mention it to someone last week and I was given this tip...
Tip no.1 Use CERAMIC HOB CLEANER just apply with a cloth and rub it in , and wash off
I tried it and it worked but did not have a lot of time to spend today, but more time and a little more elbow grease they will sparkle.
Try it!!
Tip no.2 get family to dry the doors with a small hand towel after using the shower so water does not dry on the doors which causes the build up in the first place.
Untried tip
Someone else advised to polish the clean doors with a liquid wax polish which will also stop any build up, I guess like you do a car...but this one I have not tried yet...