I’ve noticed when cleaning my new Peterson it seems like some of the stain is showing up on my cleaning rag. I don’t use alcohol to wipe the outside of the bowl at all. I noticed it when cleaning the tar off the rim of the bowl with water. I also used olive oil to wipe down the entire pipe, and it appeared to Show up on the rag from all over the pipe. So it doesn’t appear to be tobacco tar or anything. Not sure how to post a picture on here because I use an iPhone to post and can’t copy a URL. I don’t feel like the stain should be coming off of here. It’s not noticeable on the pipe itself however..... not getting lighter or anything.