Starting with a new pipe, I think the estimate give above, about twenty bowls, is the right ballpark. Most smokers
like to start with a series of partial bowls, 1/4/, 1/3, a half, to get the carbon going in the bottom of the pipe.
Though the various carbon finishes put on new pipes may shorten or eliminate the apparent need for the process,
I think it's not a bad idea to ease the bowl into regular use. Some pipes take quite a while to be fully broken in.
Some can smoke pretty well but not have that easy smoke of a well-used pipe. Some pipes are still improving after
a year.