Yesterday, I decided to pinch my wife's ultrasonic jewelry cleaner, to clean a premade coil head for the Goliath V2 (review coming soon), which was really badly gunked up, after use for 3 weeks. The cleaner is one I bought her that I know is pretty decent & has an instant 3min timer but also has a settable timer, so i set it to 10mins & let the cleaner do its "magic". This method may also work with other brands of coils but I have not tried it. It didn't remove much of the gunk at all but it did make it kind of porous & easy to brush away using an old toothbrush, that didn't get all the gunk though so I gave it another 5mins, more brushing & then got between the coil winds with a slotted jewelers screwdriver, gave it a final brush, a rinse under the tap , dried the cotton using a vaper towel & finished blowing out the water still inside the coil head. It was by no means perfectly renewed but it was pretty good looking, the main thing was how good the cotton would still be, the coil wires I knew would still be very serviceable, so I looked as closely as I could at the wicks & they seemed to be mostly clean. I screwed the head into the atty, it was still very damp with water, screwed it on to a mod & added plenty of juice to get it soaked, then fired the mod & blew air over the coils until they started to look dryish, then added more drops of juice, fired the mod until cotton started looking dry again & continued to do this for a few more times to get as much of the water out of the wicks as I could without "dry burning" or waiting for the wick to dry naturally, I wanted to use & test the coil head immediately as possible. When I was satisfied the coil head was blowing vapor in what looked to be the correct thickness (watery vapor doesn't look as thick as water free vapor), I filled the tank & started using the coil. As expected there was still some water left in the wick, I could taste it but it is nearly impossible to remove it all using the above method & experience has taught me that a few good vapes are needed to get it all out. However, the vape quality was/is surprisingly good, once the water was no longer present. This might seem like a lot of effort for 1 coil head but at $5-$6 per coil it is a little expensive to just throw out & replace the old ones, if they can be re-used. So I have been vaping on the coil now for a whole day & it is working just as I would expect a new coil to be working, no funky tastes or anything, I'm very happy with the vape quality. When this coil starts getting that off taste again, indicating it needs replacing, I will try to bring it back to life again, probably in another 2-3weeks time. If not successful, I will probably try to remove the cotton wicks & replace them, reusing the same coils. That may be an easier method of renewing the coils but getting the wicking correct on these coils looks like it will be a little tricky.