Interesting...

I believe that most styptic sticks are basically aluminum chloride (AlCl3). I know that when it comes in contact with blood (cuts/weepers) that there is a chemical reaction (stinging). Microscopically, the hypertonic AlCl3 causes the blood to lyse (break up). The aluminum creates a reaction and releases the delta-aminolevulinic acid synthetase (ALA-S) that is normally circulating in your blood. The ALA-S and chloride has a distinct odor-- combination of metalic/organic. Its kind of hard to describe exactly what it smells like.

I would take a tissue with a little hot water, and wipe the stick down to remove all the old blood and let it air dry. This is about the only thing I can think that MIGHT be the culprit...

Just a guess....

Let me know if it changes or gets stronger right after you use it?

Best,
-K