Here is the law:
21:3-2. Sale, possession or use prohibited; exceptions
It shall be unlawful for any person to offer for sale, expose for sale, sell, possess or use, or explode any blank cartridge, toy pistol, toy cannon, toy cane or toy gun in which explosives are used; the type of balloon which requires fire underneath to propel the same; firecrackers; torpedoes; skyrockets, Roman candles, bombs, sparklers or other fireworks of like construction, or any fireworks containing any explosive or inflammable compound or any tablets or other device commonly used and sold as fireworks containing nitrates, chlorates, oxalates, sulphides of lead, barium, antimony, arsenic, mercury, nitroglycerine, phosphorus or any compound containing any of the same or other explosives, or any substance or combination of substances, or article prepared for the purpose of producing a visible or an audible effect by combustion, explosion, deflagration or detonation, other than aviation and railroad signal light flares, except (a) that it shall be lawful for any person to offer for sale, expose for sale, sell, possess or use, or explode any toy pistol, toy cane, toy gun, or other device in which paper or plastic caps containing .25 grain or less of explosive compound per cap are used, providing they are so constructed that the hand cannot come in contact with the cap when in place for use, and toy pistol paper or plastic caps which contain less than .20 grain of explosive mixture per cap and (b) as in this chapter further provided.
Except as otherwise may be provided in this chapter, it shall be lawful to sell fireworks to a person only if that person is named as the authorized purchaser in a valid permit issued pursuant to R.S. 21:3-3 or that person is the owner, manager, or designated employee acting as the agent of the owner or manager, of a legally operated commercial enterprise registered pursuant to section 10 of P.L.1991, c.55 (C.21:2-37), and the permit is presented to the manufacturer, seller or distributor at the time of purchase. If the manufacturer, seller or distributor is located in a state other than this State, a purchase shall be by mail order form and a photocopy of the valid permit or registration shall be submitted with the form to satisfy the requirement in this paragraph.
Here are the exceptions:
21:3-7. Effect on existing laws; exceptions
Nothing in this chapter contained shall be construed to interfere with the provisions of chapter 2 of this title ( 21:2-1 et seq.) where the provisions thereof are not inconsistent with the provisions of this chapter, nor shall anything in this chapter contained be construed to prohibit any manufacturer, wholesaler, dealer or jobber from selling at wholesale such fireworks to municipalities, religious, fraternal or civic organizations, fair associations, amusement parks, or other organizations or groups of individuals authorized to possess and use fireworks under this chapter; or the sale of any kind of fireworks, provided the same are to be shipped directly out of the state; or the sale or use of blank cartridges for a show or theater, or for signal purposes in athletic sports, or by railroads for signal purposes, or for the use by the militia, or construed to prohibit the manufacture and sale of aviation and railroad light flares. Any provision of any law in this state inconsistent with any provision of this chapter is hereby repealed.
The question then becomes is dog training an "athletic sport" under this exception. I also know that under the New Jersey Adminsitrative Code starter pistols specifically discussed as being allowed to be used for dog training on state gamelands
All that being said, if it is common practice at hunt tests, etc. in NJ then I am just going to take my chances.
The trick now will be to find an internet seller who will ship to New Jersey.
Thanks for the feedback.