Never understood the break in tobacco idea. I do however almost always smoke Cut Virginia Plug as the first smoke in any new pipe. This is mainly to see if it is going to be a good flake pipe rather than as a break in tobacco. Bought a new pipe at the Briary. First smoke was CVP. Have smoked it twice since then. Had a bowl of Sutliffs Court of St. James and a bowl of McClellands Navy Cavendish. I smoke whatever. Some guys seem to think that they need a quick cake build up but the break in process is a part of the fun especially on a bare briar bowl. So take your time, smoke what you like, enjoy it.