I have tried 5 times doing a BVC coil with koh gen do cotton. Nothing but flooding and spitting. I feel like each time it's gonna work, but it just fails like that. I followed Rip's video but for me there is no room to stuff any more cotton down the sides. I thought of doing the horizontal coil but I think that won't work. The grooves are there but not the padding on the sides. IDK I hate to give up but for now looks like I have to buy replacements. Good coils but pretty expensive.