If you looking to get surface grim off I would suggest a cloth and warm water. I wouldn't use any other substance (soap, detergent, alcohol, etc.), and if won't come off, well than it's just character for the pipe.
If you want to remove the color from the pipe it's real easy. Buy some beeswax and do as you would if you were going to re-wax the pipe. A lot of times re-waxing will help bring out colors in the meerschaum, and yes those colors can fade over time if the pipe isn't being smoked. Now to remove the color instead of bringing more color out; when you take your heat gun/blow dryer and blow the wax off the pipe, if you get the pipe too hot the color will disappear. Heat draws the tars/oils to the surface which is why the pipes look darker when re-waxing them, and if you get the pipe too hot it will draw them out as the wax is dripping off.
I know from experience. I was re-waxing some meers and got one too hot, and afterwards it was whiter than it was before. You won't get all the color out but you can get a good amount out. My only warning is that if you get the pipe too hot you can damage the pipe by cracking it so be careful.
If you want to remove the color from the pipe it's real easy. Buy some beeswax and do as you would if you were going to re-wax the pipe. A lot of times re-waxing will help bring out colors in the meerschaum, and yes those colors can fade over time if the pipe isn't being smoked. Now to remove the color instead of bringing more color out; when you take your heat gun/blow dryer and blow the wax off the pipe, if you get the pipe too hot the color will disappear. Heat draws the tars/oils to the surface which is why the pipes look darker when re-waxing them, and if you get the pipe too hot it will draw them out as the wax is dripping off.
I know from experience. I was re-waxing some meers and got one too hot, and afterwards it was whiter than it was before. You won't get all the color out but you can get a good amount out. My only warning is that if you get the pipe too hot you can damage the pipe by cracking it so be careful.
