I regularly buy online from a great UK company called Lakeland (kitchen and household product company - one of the best in England) and they give free gifts when you spend a certain (not a lot really) amount.
My free gift with my order last week was a cloth for cleaning windows. It uses water - nothing else, no sprays or chemicals or creams, just water. You spray the area with a light mist (I used my plant mister) and just one quick wipe with this magic cloth eliminates all dirt. It is absolutely brilliant. I've just used it and been totally amazed. Lakeland are very clever to give this as a free gift because cynics like me wouldn't buy a product that said it worked well with only water.
It's called an E-Cloth and the ethos behind the company is trying to get everyone to stop using household chemicals by producing this fantastic cloth that can make cleaning safe and quite fun - yes, I have to say, it was quite fun to clean the windows, a chore I loathe and detest normally.
I've just gone to their website and ordered the car-cleaning cloths, floor mops and some bath towels.
Try it - can't recommend highly enough http://www.enviroproducts.co.uk/