It's been reported a few times that salt expansion can crack the bowl.
Oh hell no!! Don't need that. After spending hours reaming, sanding, trying not to screw up or scratch the finish with the sandpaper.
If it needs refinishing then no big deal as long as its not deep scratch or sand marks. But after all that, cleaning, polishing the stem, possibly making repairs to the stem and you go to sanitize it and POP!!!
Don't need that. I do have a Retort setup. No fancy burner or anything just figured I'd use candles.
My understanding is you can just keep boiling the alcohol until enough contaminants prevent it from boiling. You don't have to keep changing it when it gets a little dirty.
This method sounds safer than salt to me. When researching how to sanitize and de-ghost a pipe, I never read anything about it cracking the pipe. But thinking about it I understand the mechanics of it.
The salt can soak up the alcohol, possibly harden, expand and POP!! I was concerned about using boiling alcohol on a gourd. Right now I couldn't get salt or cotton balls where the carbon buildup is. If I could take a picture I'd show you. I used a dental mirror to see it with a flashlight.
It appears they used something to keep like a draught hole open in the carbon. So if I put in salt or cotton balls it would set on top and not penetrate the center. Pretty sure a retort will penetrate. Only possible problem is the shank extension I believe is bone.
The alcohol could remove the glue on the shank extension. Or the heat could further damage the already cracked extension.
The salt might work its way in but if it can crack a briar it will destroy the shank of the calabash if it expands.
The carbon is about 1/4" thick around the hole in the center. Picking at it has been a pain. Didn't consider the brushes. Sort of out of sight out of mind type thing.
Figure I can start with the draught hole brush, then mortise brush, the bowl brush, then possibly a toothbrush or/and a nylon shotgun barrel brush.
I have several gun cleaning kits. Some contain specialty brushes for tight areas, different types of weapons. Also some of them the brush forms a dome to protect the bore from damage. Most brushes are just cut off and the end addressed to remove burrs and sharp edges.
Thanks for the information about possible damage. Definitely something to consider.