Burning Vortex Bowl
I don't know if it's just me... but after about.. 15 sessions with a vortex bowl, it starts to get black on the upper sides of the bowl and all around the spire. I try to get rid of it by excessive scrubbing or even running a razor blade to scrape it off, but to no avail.
Has this happened to any of you and will it ruin the flavor of future shisha sessions? How do you get it completely clean?