Rating: 5 / 5
After doing a bunch of online research some years ago, I learned that the difference in efficacy of DEET concentrations came down to time. 10% is as good as 100% for a short while, but 100% lasts a lot longer. That holds true for non-DEET vs. DEET mosquito repellents as well, the non-DEET repellents work well for a short while, but quickly dissipate.
Along comes time-release DEET, the brands I know of are 3M Ultrathon and Sawyer Controlled-Release. The time-release formulations are down in the 20% to 30% range, but due to their formulations stay effective as long as much higher concentration DEET. But, they are not as gross! DEET is really unpleasant on the skin and dissolves plastics.
Well, recently I was at REI and saw this new Sponge-Top applicator version of the 3M Ultrathon. I took it backpacking and it was awesome! I didn't have to get it on my hands at all! Just squeeze a tiny bit out onto the sponge top, dab it around behind my ears, on the back of my neck, on my ankles and legs, etc. Not only is it so much less icky, but I feel like it lasts longer too because half of it doesn't end up coating my hands.
This is an amazing scientific development and whoever thought of it should get a medal!