There isn't such a thing as an "airsoft smoke grenade" as far as I'm aware.
There are lots of different kinds of smoke grenades, but most of them are pyrotechnic, which means they require ignition to work. Pyro is not welcome at most fields and, even if they are, only well-known members of the community should be allowed to use them.
There are some flameless smoke emitters, but I'm unsure as to whether or not they will be allowed.
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