I've been thinking about what kinds of weapons a Sentinel might want to have on hand to deal with weaponized nanites. I initially leaped towards plasma weapons, but the beam width is probably too narrow. I started wondering about microwave agonizers or the "stun" mode on a laser pulser but figured the nanites wouldn't react much to microwaves and there wasn't enough mass for the pulser to generate a plasma blast.
Then I had a realization....Nanites should have a very high surface area to mass ratio thanks those tiny manipulators & propulsion systems and go up like concrete dust or toner to almost any open flame. So ye olde flamethrower (or the Torch spray weapon) is probably a viable anti-nanite weapon. Napalm would also be a good choice.
I'm wondering about grenades. I think concussion would disperse the nanite cloud temporarily. Plasma, without a shockwave, would not break up the nanites but should destroy them.
I'm not rules lawyer, I'm a rules engineer.