According too OFF'S site, it works on them plus ticks, and the usual nasty characters.
Cheaper than a Thermacell, not knocking them, I guess you'd have too do a bug to bug comparison too see what's best for the money.
 Treating ALL your clothes with Permethrin, and using the bare minimum of Deet will go a long way in avoiding ALL bug bites.
The Thermacell/Clip-on just gives you more options around camp or in a canoe IF there is no wind.