Butterfly Net:
One end of this 6-foot long pole supports a wide metal hoop covered by a thin mesh net. You can use this to sift objects out from material capable of passing though the net such as sand or water. You can also use a butterfly net to capture Fine or Diminutive creatures as if it were a net (weapon), though you don't need to re-fold the buterfly net if you miss, and you use the handle of the butterfly net like you would the rope of a net weapon.
So it uses the rules of the net exotic weapon.
So my question is if you entangle it, can the swarm still attack you if you control it?
How large is this net - would the whole swarm fit in?
If it works, you'll have the swarm at arm's length, and it should not be able to attack you.