First let me say that I hadn't heard of this product until your post. I went to Google, typed in the product name and was taken directly to the website of the manufacturer (distributor?) for the product. At first I thought it was a product meant to do actual building of pieces, and it might work good in that application too, but after going to a bunch of the other links I believe its meant more as an adhesive for rock work. While there may be some real benefit to bonding rock structures together to insure stability, I for one would hate to have to remove anything that was permanently bonded together into a big pile O'rocks. Finding aquarium / fish safe products is always of value, and I for one appreciate the link to this product. I will have to do a bit more reading on it, as the price seems reasonable.
On a side note: If you want to use a product such as this to stabilize your rock structure but not permanently bond the rocks together, I would think that if you used a parting agent on one rock, and nothing on the other you may be able to form cradles that lock the rocks together but allow for easy removal one rock at a time, think jig saw puzzle.
