Is that what happens when you only hold the shank when you're smoking a meerschaum? I've been trying to experiment myself with a number of meers.
Meanwhile '15 MM965 in an Old Dominion while browsing this forum and eBay... I like to live dangerously.
The oil from ones fingers & hands will colour/stain a meerschaum. [Thinking out loud here; a meerschaum that has been treated with wax probably less so]
Some guys wear a cotton glove to hold their beloved meerschaum.
Far be it for me to criticise others way of doing things - for many a carved block meerschaum pipe is something that they've saved for quite a while, so for them, it's a rare luxury item - but from my point of view, it's too much fuss to smoke a bowl of baccy.
Although I now have a few meerschaum pipes, all were won on ebay at very reasonable cost. So apart from ensuring that they're stored in a way to avoid any damage and never taken outside, the only trouble that I go to is that I wash & dry my hands before handling them.