We will be renovating our bathroom and are thinking about using slate tile on the walls by the tub/shower. (1x2 mixed slate brick tile made by MS International) I know that we'll need to seal it once or twice a year, but I'm concerned about the upkeep. Is slate a bad idea for a shower? Is it difficult to clean? I know that you can't use the regular household cleaners that you would use on ceramic or porcelain. Any advice would be appreciated. Thanks!