I do not use my Zippo for anything daily and have found that wrapping it in 3-4 layers of Saran wrap retards evaporation for many weeks. A couple of rubber bands keep the Saran in place. I slip a small note under the wrap with the date filled.

I also carry the Tabasco bottle and that works very well. About 2.5 fills in the bottle. The Zippo canister is also very nicely made and carries more fills.