Actually the wick itself changes flavors nicely, but the juice leftover in the tank may still "taint" the new flavor, as I've experienced. Depends on how strong the current flavor is compared to the one you're putting in. I use the drill bit method, so pulling the wick, rinsing the tank, blowing it out, and then drying and reinserting the wick is easy when changing flavors. This way I get full flavor from the new juice, and it doesn't hurt to clean it anyway. Though some people just vape the whole tank or pull out the remainder with a syringe and refill with the new flavor. With a coil that's wrapped directly on the wick, rather than the drill bit method, that's about the only way to do it.