I used to use a coil for 1 to 3 days.
The used coil went into a cup to soak next to the kettle; when I boiled some water I'd add hot water to the cup.
On Sunday's I'd take the used
coils out of the cup, remove the old wicks, dryburn, and rewick with cotton.
Rewicking those tiny
coils is not an exact thing; sometimes it's too tight, or something, and I might use that coil for a day or less; other times a coil seems to come out perfect and I'd use that for several days; on average I'd use a coil for 2 days.