The buildup of old e-liquid that settles in the threading of your cartridges and batteries can shorten their life and hinder their taste and functionality - but don't throw them away just yet!
Go through each of your cartridges and find the ones that looks the best, still have a decent flavor and vapor pull, and use them up until they need to be refilled. If they are just too dirty to use, add them to the pile. Once you have collected a number of empty, dirty cartridges, it's time to clean them!
Here is what you'll need:
1) A microwavable bowl (size depends on the amount of cartridges you want to clean)
2) A pot for boiling
4) A large spoon for stirring
6) Wine tool/nail/bobby pin (anything you can use to pry the white cap off of your cartridge)
First you'll want to get your supplies and lay them out. Try to find an area that can supply ample room for you to work. I suggest the kitchen, as this is where you'll have to go eventually.
Begin by carefully and gently prying off the white end-caps of your cartridges with your wine tool/nail/etc. These caps are typically made of plastic, so you don't want to crack them, and be ye warned - you might have white caps flying through the air!
**Some cartridges have a new part inside them - a clear, little, rubber piece that makes this process a total pain. Though, I do believe that was the manufacturers point! However, you'll find once you remove the plastic part, you're cartridges will have an even better pull and are easier to refill. You can keep this piece or throw them away. It's totally up to you.**
As you remove the white, plastic caps, place them in your microwavable bowl. I also put the little rubber condom pieces in there.
Then, put your cartridges in your pot.
Once you've finished, add water into your pot (just enough to cover the bottom) and swirl your cartridges around with your spoon. If your cartridges are really dirty, you'll begin to see the water change colors. Do this for a minute or two and strain the water out. Fill your pot up with water again, a lot of water wont hurt this time - just make sure the cartridges are covered. Let this boil for about ten minutes. **DO NOT BOIL THE WHITE, PLASTIC CAPS! Extreme heat will alter their shape** Only boil the cartridges!
While your cartridges are boiling, take your microwavable bowl with the caps and rubber pieces and add water and a splash of hand soap to your bowl, fully covering everything, and stir. Zap in the microwave for about 30 seconds or until ALMOST hot, and stir again. Now you'll want to strain and rinse these. Pat dry and let sit to finish airing out.
When you've boiled your cartridges for ten minutes, I recommend straining them and repeating the process. However, once is probably enough if they aren't too dirty. Now, it's time to get your strainer. While in the strainer, rinse them with cold water, and then sling any excess water out of them.
Lay the cartridges out on a paper towel with the open side down, and leave them alone to finish drying. I recommend you give them as much time as you can. You want all of the excess water to completely dry before refilling them; otherwise, they won't taste right. If you're impatient like me sometimes, you can use a hair dryer to dry them out. Just don't use the "hot" feature. I suggest your use the cold temperature, so you don't risk burning the cotton.
Now, there you go! You have clean, like new cartridges, that will taste and look better. If you have any questions, let me know!
Thanks for all of your support and Happy Vaping!