Im curious how long each of these will last

depends on the juice you are using. some juices leave a lot of gunk behind.

I have one particular type of coffee juice which is good for about 5mls before cleaning.

When cleaning, I dry burn till all fumes/vapor are gone and the coils are glowing. A quick rinse and then off again. Been using the same coil 1.5ohm coil on and off for a month now.