I use an unglazed 'stoneware' bowl - I find that the rough edges of the bowl build a nice lather.

With this said, I often just build a lather in the bowl that my shaving soap is in; wet the brush until it is 'full', give it a shake to get rid of excess water and swirl it around inside the soap bowl until the lather is built. Makes lather quickly and I just leave the excess in the shave bowl to dry. I'd like a scuttle but I have the feeling I'd never use it since I hardly ever use the dedicated shaving bowl that I have.