Bob,"Dirt" isn't the issue. The issue is that your warm hands will rub away the beeswax coating the exterior of the bowl -- and its the beeswax seeping into the warm bowl as you smoke that helps the meerschaum to color evenly and (relatively) faster than it would otherwise. And for people who love the look of a well-smoked, well-colored nut-brown meerschaum, smoking it is only part of what it means to "fully enjoy it." The other part is seeing that that coloring happens in the best way possible. (I'm sure there are meerschaum purists who would sniff at anyone who doesn't have a properly colored pipe.)
Bob
That is interesting insight, thank you for the input. I thought that the beeswax played a part in coloring, but that the majority came from the tobacco juices and tars seeping into the porous meerschaum mineral and henceforth, turning it varying shades of brown. I will have to do some internet research on the forums and elsewhere to figure out how to go about getting some proper beeswax to recoat the bowl from time to time to help the coloring process along and the process of applying it as i have never done it.