Hello Lin & Larry,
I acquired and used a similar product from Davey's Arborist Supply when I was in the tower business. It was called a Bokat Rope Washer and we used it to clean lines which we used in tower work. It was a plastic tube which had a hose fitting allowing water to be injected into the tube while you pulled line through it. It also "astro turf" type plastic finger inside which scrubbed the line. Based on it's dimensions, you could easily use it for chain as long as the diameter of your chain was not too big.
I took a few minutes to Google it and I found the product on a PMI website...
PMI Rope : Equipment and gear for edge abrasion and cut protection, end terminations, marking, cutting and measuring and cleaning your rope.