I like to use Horticultural Oil for Thrips. I use Avid insecticide for a number of pests (and it doesn't seems to bother the good insects) and thrips is listed but it says it only suppresses them which to me means it doesn't do much so I add the Horticultural Oil (Ultra-Fine or Ultra-Pure) to my spray regimen and it works great. I ran out last year and kept forgetting to get more for this year and the thrips were horrendous. The oil is also good for spider mites, aphids, and other pests; it gums up their digestive system and also suffocates them.
Although I have never used Murphy's Oil Soap I'm sure it does the same thing.
