You could try borax. I personally haven't dealt with the green worms of doom. My aunt has but I know she uses chemicals. If 7dust won't kill plants I would imagine Borax is probably going to be okay. Wash it well after harvesting obviously.

Vinegar can be handy and it might be worth a shot to try. Just spray it on. You can also try removing the leaves if you're able to that have the eggs on them. It won't eliminate the problem, but might help it go a bit faster.