Ditto Anasazi! Right now, I am using Old Crow bourbon to clean my briars, and PGA to clean my meerschaums.
I have never liked the consistency of PGA, especially with briar. With meers, it's not so bad, as it seems to get the job done quick enough, before it begins to evaporate. Bourbon give me the time I need to work with it, before it evaporates, as well as, it won't strip wax off the bowl as easily, if I get a bit careless.
When it comes to bourbon, I take time to read the labels. Some of the cheapest bourbons are half pure grain alcohol, which defeats my purpose.
I love the way bourbon makes my pipes smell during the cleaning process, as well as after they have a few days to rest. I previously used Jim Beam, but I decided to give the Old Crow a try, as it was pure bourbon and 1/3rd cheaper than the Beam. I am pleased with it so far, and will probably just stick with it from now on.
The only thing about the Beam that I like better, is that it is a decent enough bourbon to drink if I am all out of single barrel varieties.