Can anyone help with a solution that will clean off grout/adhesive from tiles. I have recently tiled my kitchen and used the grout/adhesive mix, the tiles are black and are not gloss. Obvioulsy i wiped the grout as i went along but now the tiles look 'cloudy' and really need cleaning somehow. Have tried various cleaning products to no avail. Does anyone know of anything stronger to clean off the dried grout? Thanks