Smooth. (read warning)
The charcoal I use is in small granules, a little bigger than the poppy seeds on a bagel.
This can pose a fire hazard. The activated carbon may heat up, and it may not go out when it touches a surface. As the paper burns away, the charcoal may fall out of the joint and burn your clothes or carpet. Be careful. I suggest putting a little cardboard between the pot and the coal so that you can taste when to stop - the way you normally realize when to stop when using just a cardboard filter. or just pay attention!
This works great in pipes, and if you heat the coal hot enough, it won't go out so you can toke without lighting.
The charcoal I use is in small granules, a little bigger than the poppy seeds on a bagel.
This can pose a fire hazard. The activated carbon may heat up, and it may not go out when it touches a surface. As the paper burns away, the charcoal may fall out of the joint and burn your clothes or carpet. Be careful. I suggest putting a little cardboard between the pot and the coal so that you can taste when to stop - the way you normally realize when to stop when using just a cardboard filter. or just pay attention!
This works great in pipes, and if you heat the coal hot enough, it won't go out so you can toke without lighting.