Is it good? Well it won't hurt anything but it isn't the way it is intended to be used and it will increase the leach-out rate.

Granular organic fertilizers will only work in containers if there is something in there besides a sterile potting mix to provide the needed bacteria for it to work. Organic fertilizers work well for in ground plants because of all the natural soil food web in the dirt but in containers, which need to be filled with a well draining potting mix rather than dirt, there is nothing to convert it to a usable form by the plants.

Dave