i had a conversation once with an avid aqua gardener (he happens to be the postman at workjob) and he said that the main bulb will send off sort of a large short root that will turn into another bulb right next to the main bulb and then you just cut off the smaller bulb and replant. this is in the case of a onion plant, not dwarf variety, but i would imagine they are the same in their propagation.
so no, they don't propagate like vals, since vals send off runners. all of my vals send off runners that are at least a couple inches long.