Thermacell works great if you're sitting still and the vapor can waft itself around your area. Not so good if you're walking/stalking or there is a little wind.
For a odorless spray on try Permanone or Permathrin. It's a product that you put on your CLOTHES ONLY...do not put it on your skin. It has a little odor when you first apply it, but dries odorless and does really good for skeeters, tics and chiggers...so I'm told by friends that have used it and by what I have read on this site. I found it in Wal-Mart last night...in the camping section...not where there other insect sprays are.