I don't know how well bluing works on synthetic fabric. Never thought about it. I do know when I saw some in a little country store a few months ago, I was really shocked. That's probably the first time I've seen it in years -- literally. I didn't know anyone used it for anything, still.
However, I'd paint myself blue as anything if I thought it really would help keep mosquitoes off me! I can't imagine why it might help, but I swear I'd be blue as a goose if I thought for a second it would keep those little devils from biting me! I hate mosquitoes.