Deoxit is amazing, it really does what they claim. Especially on a single cell (lower voltage) like a 1.2v Nimh light.
It has made some of my lights a lot brighter, especially on low. The brightness increase in my Nitecore D-10 and my Fenix LOD is excellent. I was skeptical before. It does not seem to lose anything over time, even on lights that go in and outside in the cold weather all the time.
(They might get a little condensation on the inside parts).