I have tried a HUGE variety of "natural" brands and types - all of them seemed to work for a while. Then, when really put to the test, failed me - and badly.
For winter use, when you're not doing heavy physical work (in other words, when you don't need something very effective) a crystal is good (I find the so-called liquid crystal useless, btw). I've had similar results with this one
http://www.amazon.com/Toms-Maine-Deodor ... B001FB5O9A.
I think those two I listed are the best of the naturals. But, if you're going to spend a week hiking in the tropics, I recommend lots of chemicals ; ) (In fact, when we travel to hot places, I even ditch my American Chemical Solid & buy a local Chemical roll-on that is more effective)