Cleaning is a crapshoot. it may work for a carto you hardly used and did not singe (like a prefill you didn't like). but once a carto is well-used the coil is coated in baked on juice and weak and no amount of cleaning wil get that off.
What is expensive about $2 for one week of use (or even 1/2 week for heavy vapers) out of a carto? IMO the juice is the more expensive part. $2 for a week is nothing is nothing compared to what smoking cost.
Learn to use them, use suitable clear juices, and you will get good carto life.
Short version of how I fill 1ml cartos (like Bolt, Bloog, Boge) and keep them damp
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The carto has a 1ml capacity. You need to aim towards putting 1ml in. I hold a tissue on the threaded end hole (or put a carto cover's spike in the hole), tilt the carto and drip in 18 drops (waiting longer for the first few to soak in), Then I wait 15 seconds. Then I see how many more it will soak in easily (usually 3-6, occasionally more).
Then I clean it up - clean threaded end, tilt open end down into tissue and puff into threaded end to clear the air channel, then while still pointed down I just touch a soft bit of tissue to the top of the stuffing to sop up excess (to help prevent leaks).
Then I let the carto settle. I use juices with 20% or less VG so 15-20 minutes of laying it on different sides and on end is plenty of time for every bit of stuffing to get damp.
While vaping - any time the vapor seems light, dry, or tastes the tiniest bit off or loses flavor, or if the caro is getting abnormally warm, I add liquid. I also occasionally look at the stuffing (especially before putting a fresh battery on or before going out) and if the top of the stuffing looks white, I add some juice. No settle needed when just keeping the carto damp. And if you do not keep it damp or if you use juice that is too thick (too much VG) you will singe the carto and that adds a bitter taste. I use a simple plastic or delrin drip tip in place of the end cap so it is easy for me to remove that to look at the stuffing, or add juice with the carto off the battery.