You can get pyrithrum spray in a encapsulated spray. Pyrithrum disappates quickly. So the encapsulated formula hangs on untill the critters walk on it and then it's like a land mine. Normal pyrithrum spray will work just make sure it's only pyrithrum and spray every 3 to 5 days.

If you get time release be carefull about harvest time I'm not sure how long it last. Could be bad for harvest.