I installed the floor tile in my bathroom and it came out great. I had a guy do my plumbing and I had some outside work and I really needed the shower done. He said he did tile: He lied. He didn't use spacers, I bought white mate hexagon tile and you can basically see the sheets plus the thinset came through the cracks and it was hard by the time I saw it
HOW DO I REMOVE THE THINSET FROM THE CRACKS (AS CHEAPLY AS POSSIBLE)? NOTE: they are hexagon tile there are no straight lines longer than an inch.
PS. He then said it looks ok from far away and that it was an old house anyway (took a lot for me to not knock his teeth out and tell him he was old anyway).
when you install tile i learned to clean as i go, something that "installer" should have done. but that doesnt help you now. (2) tools i have used to clear motar from joints - utility knife -- does a good quick job but care must be used damaging yourself and the tile. In your case a grout removing tool (available) at home improvement stores, just be careful not to go to deep as you may damage the liner under the motar. It will not be a quick job but you can get a tool the same size grout line - hope this helps and is not to late