I think I know what Vern is talking about as I just saw Bob on TV doing a short tip on using a sawdust/sealant mixture as grout between end grain wood blocks, and to repair cracks and gaps in other wood floors. I became interested because of the beautiful end grain block floor. I will surely install one in the kitchen/dining room of my planned new home. The blocks were spaced about 1/4 inch apart and used an oil based product mixed with sawdust to hold them in place and also to fill the spaces between them. The end result was a very nice looking floor like I have never seen before. I am also looking for more info on installing this type of floor, and how it will work with hydronic radiant floor heating.