Can someone please help me about the cartridges information. I have never bought one that you change coils in. I know nothing about them. I have always just bought the whole knew cartridge. Is there a way to clean the ones that you dont change coils in? I know absolutely nothing about cartridges and coils or anything associated with them. Please help me on if there is a way to clean the ones that dont have the changeable coils. It just stops pulling any vapes threw it. Help please