Sorry Rob...not "dry" as in unmixed, just mix it on the dry side. It'll hang together, sink to the bottom and force out the water. Never tried dumping it completely dry, but I'd be concerned that it would separate out due to varying particle size...you wouldn't have "concrete" in the tube, but just layers of stone, sand and cement.
I've also dumped completely dry sakrete around posts (and my bridge piers) and it works quite well. Just try removing them later...that's different than having standing water in the hole.
