Tomato (and pepper) Hornworms

Saturday, my tomato and pepper plants look great.  I check the garden
mid-day Sunday and, HOLY COW, i'm missing 20% of my tomato foliage/
stems...about 20 tomatoes have been munched on...and my sole hungarian
pepper plant has every fruit on it munched and all but two leaves are
missing.

I spent 1/2 hour or so plucking and killing hornworms...about 15 of
them.

Any solution to this besides checking the plants every day?  How long
do these things go on?  Checking online it looks like they might be
around for a couple of months.  Some suggest parasitic wasps...but not
sure how you go about managing those.  Another suggestion was "bt"?

Help?

--
John