I did number 2 again 20 minutes ago. Hoorah!

I did number 2 a few months ago after seeing it originally on LH, (similar desk to mine actually, so I got the Ikea one as well).

The only problem with this is that it stinks! However, I do use it quite often by taking off the shower head, leaving it in a bowl of the stuff overnight (usually outside where I can't smell it), then in the morning rinsing it under fresh water. Marks and stains gone!