Assuming those weights are lead, weight is weight. (The density of water renders a lot of things that are "weights" on land less useful underwater, as anyone who has tried to pick up rocks to make up for underweighting has vividly learned.)
BC pockets are not designed to hold weights, though, and especially hard weights will wear through the pocket material or even damage the stitching, depending on the BC. In addition, the points already made about weight stability are important. It is rather miserable to dive when, if you change position, you suddenly have a big change in balance. However, if all you are trying to do is figure out where you need to put weight to get properly weighted and balanced, using things like what you show may be quite adequate. Once you determine what you need and where you need it, you can acquire weights that are the right amount and size, and the proper methods of securing them.