Hi, Just installed some glass mosaic tiles. Read lots of forums first, and having grouted them in, left them for 15 mins before wiping with a sponge, repeated this 30 mins later, and then about an hour later. This left a very faint haze which I left until today to remove...only it is proving very difficult! The mosaics are glass, but what I hadn't realised is that the larger brick is glass front with paper image stuck on behind, smaller silver brick looks to have had a silver paint/layer put on top. The larger block requires some elbow grease, but haze should come off fine, the smaller silver bricks are a nightmare, and it literally takes up to two minutes to clean one silver brick with lots of rubbing with a wipe, and then finishing with paper towel. There are over 400 of these little silver bricks needing to be cleaned. Is there a product I can use (a spray maybe), which won't stain (it is grey), and won't damage the face of the silver bricks (they seem pretty robust against a wipe, don't know aggressive a spray chemical would be)? Any advice appreciated (image attached).