These tablets have been around for 20 years. I think the original idea was that the container they come in fits in a standard USGI canteen pouch, so it would be easy to keep on your equipment. I really don't think you could, or that it was designed as a sole way to feed yourself. I believe it was thought of as a supplement to whatever else you had or could gather. Never tried them myself or heard any first hand reports. I have to go with Chris, for the price + shipping you could do a lot better.
Dave