I recently switched from a Juul to a Sourin Drop. I got a bunch of different Naked 100 salt nic juices. Some of them seem to be fine when I vape them but every time I use Brain Freeze (Stawberry, Kiwi, Pomegranate, and Menthol) it quickly within first use creates a bunch of yellow and black build up on the cotton and coils. I make sure to do a priming period as instructed. Are some juices just bad for coils?