Decades ago I purchased a dedicated meerschaum chamber reamer. Click the address for a picture of it on Flickr. Its performance is mediocre on thick, highly encrusted chambers but works well in keeping the chamber clean if used regularly. The fact that I have not seen anything like it on the market in recent years is probably an indication that it is the meerschaum pipe equivalent of Yugo automobile.
https://www.flickr.com/photos/41273109@N02/35033634131/in/dateposted-public/
https://www.flickr.com/photos/41273109@N02/35033634131/in/dateposted-public/