The Skin so soft stuff really gained note for blackflies, it has never been effective on mos. to any degree, though it is marketed for use on children because it is less nasty.
There is supposed to be a new Cutter product that is not deet, and is as effective, but somewhat nicer. There was a lot of talk about it last year. So far it hasn't reached my neck of the woods. Cutter used to be the best product before Muskol and the various deet products.
Mos. suits and citronella jackets are very effective.