Thank you, luckymom. This house is still a work in progress; no doubt I'll be ready to remodel by the time I get everything like I want it, LOL. The slate is called Multi, and has charcoal, rusts, greens, golds, deep aubergine, and a little cream tones. As I mentioned, it is gauged. It is not the Chinese Multi that you see at Lowes and some home improvement stores, although it is similar. Some of the Chinese Multi has purple, or irridescent colors (very pretty) but is more fragile and flakes more. Also some of the Chinese Multi I looked at is not gauged. Here are some closeups of the Multi--hope this helps!

So the large timber work is going in and by now the roof is installed. The client has chosen a granite tile for the floor in a 12"x12" size. Now I'm waiting for him to decide on the railing detail across the front. The NTCA just sent out a Webinar training course on Exterior Tile Installations. The info for this is below: Strategies for Exterior Tile Installations Meeting Description: Learn about the key strategies to a successful exterior tile installation. Understand the importance of careful tile selection. Gain the groundwork necessary for substrate preparation and proper mortar and grout selection. Not only does this webinar walk you through the importance of planning, it also sets effective approaches for exterior installations to ensure a well-executed project. Meeting takes place online Date:Wed, Jul 22, 2015 Time:01:00 PM CDT Duration:1 hour Host(s):Jim Olson- GOLD Presenter: Tom Plaskota Tom Plaskota,Technical Support Manager for H.B. Fuller Construction Products, Inc. develops and markets technologically advanced solutions that add value to commercial, industrial and residential construction. Tom is responsible for managing the field support team that develops and communicates technical information and provides technical service. He is actively involved with the National Tile Contractors Association and is a former Industry Director for the Chicago Chapter of the Construction Specifications Institute. Tom has over 30 years of experience with construction methods, testing and materials. He is certified as a Construction Documents Technologist (CDT) and holds a bachelor’s degree in civil engineering from Valparaiso University. Sign Up here: https://cc.readytalk.com/cc/s/registrations/new?cid=q7aasu5s6gfp

Rent a steamer or hire a company to do it. My mother in law has a comercial grade steamer and we have used it to clean everything including slate walk in showers. It is amazing how well it works. She used it on her tile floors that are in her house that was built in 1942. The tile floors had been waxed by the original owner for many years. The steamer pulled out all the built up wax and grime from 60+ years and they now look great.

Try posting this on the bathrooms forum. I'm sure someone will pipe up with the best sealer for your situation. You might just search that forum for slate sealer and see what comes up. Below I linked to Bill V's FAQ. He's a frequent and helpful pro poster on the bathrooms forum. if you scroll down the FAQ to the "What is the difference between a water based sealer and a solvent based sealer? How do you know which one to use?" question, you might get some clues as to why your current sealers are not performing well for you (then again, they might be solvent-based too, in which case I don't know what to tell you). If you continue scrolling down to his links button, you will see on the links page that he lists Miracle Sealants and Stone Tech Sealers, so those might be places to start with. You have two separate problems: you don't like the performance of the tile, and you don't like the appearance of the pattern/grid. It's possible that if you fix the performance problems, and maybe find a way to darken your grout, you can live with the tile. Personally I really like slate. But it's your house and if you hate it, do what you have to do. If you remove it you might be able to get it collected by a company that crushes slate for landscaping, rather than having it go in a landfill. Here is a link that might be useful: Bill Vincent FAQ