Mine last less than a week... because I want to rebuild it

I'm sure that will fade over time though and they will last longer:
I do 28ga kanthal micro coil at 1.3 to 1.6 ohms. I run it at around 8w.
After every tank or two or three, I pull the cotton, dry burn, let it cool, use a "dust off" can of compressed air to blow off any lingering crusties, rince with hot water, dry burn again, rewick.
I'm recoiling Fogger v3 (with vertical/chimney coil set up) and KFL+ clone with single horizontal coil.
the coils have looked just about brand new when I pull them for the rebuild, but again, I'm rebuilding every few days.