Once you level your slates and the seams super glue the seams every 6" like a dash this keeps the slates from ever popping @ the seam then fill the seam with Bondo or Durhams Rock Hard Wheat Putty. I find that Bondo works better then Durhams less chance of it crumbleing or causing speed bumps. Most people just dont like the small of Bondo or wait to long to scrape the excess off with a blade or putty knife.
Unless you really scrape it good and heat it off.
It's pretty much impervious to pretty much everything else......
And if you're going to heat it off, make sure you have something underneath to catch the runnoff, it's tough to get out of carpet when it dries.
It's bees wax the stuff you get from Muellers is soft all the time. The blue stixs of wax I havnt tried it yet. In all honesty bondo is the way to go unless you are setting up a display table or constantly moving all the time. Wax just makes it fast and easy on disassembly. As for cleanup Bondo and Durhams you can pick up out of any floor with a vaccum. Also with Bondo you dont get the white line or dull colored line running across the slate were the seams are. 98% less go backs with bondo wax I would say its fifty fifty unless you super glue your slates together.