The easiest deep clean job you can do is to disassemble the atomizer and allow all of the components, including the coil, to soak for 30 minutes. Soaking the components in hot water may clean them up a little, but you will probably have to use something stronger to get rid of a nasty taste.
A q-tip is great for wiping down the inside of the atomizer, and it’s a gentle way to clean the fragile coil. But to clean the gunk out of the tight spaces like the airway, you’ll need to go MacGyver.
Chain vaping or not having enough e liquid in the tank are common causes of coil damage as the wick does not have time or enough e liquid available to soak up e liquid between puffs. A dry wick due to this will cause your coil to burn.