Anything can be declared a religious symbol and carried for purposes of practicing worship. When the first kid goes to the hospital with a Kirpan Dagger wound, and it will happen, the rules will change again. In the mean time...
A Reading from the Book of Armaments, Chapter 4, Verses 16 to 20:
Then did he raise on high the Holy Hand Grenade of Antioch, saying, "Bless this, O Lord, that with it thou mayst blow thine enemies to tiny bits, in thy mercy." And the people did rejoice and did feast upon the lambs and toads and tree-sloths and fruit-bats and orangutans and breakfast cereals ... Now did the Lord say, "First thou pullest the Holy Pin. Then thou must count to three. Three shall be the number of the counting and the number of the counting shall be three. Four shalt thou not count, neither shalt thou count two, excepting that thou then proceedeth to three. Five is right out. Once the number three, being the number of the counting, be reached, then lobbest thou the Holy Hand Grenade in the direction of thine foe, who, being naughty in my sight, shall snuff it."
-- Monty Python, "Monty Python and the Holy Grail"