X2 on Thermocell. I've used the clip-on Off "thingy":D but not with much luck. ThermoCell on the other hand work great. I had one Turkey hunting one time and I after sitting in the woods for an hour at sunrise one morning, I thought to myself..."huh, no mosquitoes" and turned it off, left it by a tree and put a sneak on a turkey. Big mistake within one minute of leaving that tree and my Thermocell...mosquito cloud!!!
I've also had luck with Skin-so-soft but have not used in many many years.