How to stop smelly fuel

I’ve got one or more hand warmers that stink of zippo fuel
When I use it any idea how to stop it or am I using to much

Have you tried repacking the reservoir with carbon felt for those? Also we just introduced terpenes in a straw (deodorizer) so they can be shipped via the cheaper letterpost method.

One thing to keep in mind. This past year I have been installing an Espar style diesel cabin heater in my van that I camp in during winter. When the fuel is not totally combusting, you get more fumes that smell. The same could be true for handwarmers. Also any spilled fuel that has evaporated on the outside of the case will give off fuel odors from the residue that remains after the liquid evaporates.