There are times you just wanna clean a coil. I stopped doing it mostly because I didn't know how clean they were getting, and they tended to die unpredictably. But, I also wanted to find out that information for myself. Etc.
It's a perfectly good rationale to switch to rebuidables but the answer to how to clean a coil is not buy an RTA. There are various methods of cleaning them, and they may or may not be successful. Some coils you can get sorta clean and all, but there are methods to cleaning coils that will give them a few days more life, how healthy they are is debatable, but it can, in fact be done. I know this because I have done it. More than once.
Anna