Coralline is a very pretty encrusting marine algae. I would soak it in white vinegar before using it. Maybe get a bottle brush for the U-tube part.
I can bring it into town in the next couple of days. Since I am so far south Brooks City Base off 410 and IH 37 usually works well as a meeting place (rather than LaVernia! lol)
We can work out the details via PM