Back in the day, especially with the Protank single coils, I used to rinse in hot water, soak overnight in vodka, let dry for several days and revape. Like @Earthling789 said, it's great for getting one flavor out of the wicks. Then, we discovered that we can rebuild the Protank coils so now, when I use the old tanks, I just rinse the old coil and toss into a "rebuild someday" pile. With my Triton tanks, I have an RBA coil for them but with coils so cheap, I've just been holding onto the RBA for the someday should I not be able to replenish my supply of ready-made coils.