I watched video by Rip Tripper on rebuiding a mini PT2 coil and he puts the cotton in the coil at the end. Would it be correct to say that I do not have to build the entire coil myself, I could just buy new coils and pull out the stock silica and simply replace it with cotton? That would save me the trouble of fiddleing with wrapping the actual coil. Is there some benefit to doing the entire coil yourself other than just saving money? Or can I simply replace the stock silica with cotton? I know you can customize the ohms but I'm not worried about that I would just buy the ohms that I want on the replacement coils.