The grenades are not functional as a "pull pin and throw it" weapon: if you look on the fuse assembly, you will see an open pin hole that would normally be taken up by the metal pin that holds the striker and striker spring in place. They could be made functional in other ways, but I won't list those ways.
The HDP-1 does appear to be the real thing. It is used as a booster charge to initiate the main explosive such as ANFO or the explosive slurry mixtures used in commercial blasting and clearing of rock for construction purposes.