I’ve seen some good stuff made from coconut shells, I have a couple of ornate drilled and carved lamps and have made a few bowls myself scraping away with a Swiss Army Knife while laying in my hammock in Thailand, too hot to do much else. I’m also familiar with Brita type water filters and the term “activated” charcoal, but didn’t know that the very dense coconut shell was the source, or what “activated” meant. It kind of blew me away that 3 grams of activated coconut charcoal has the surface area of a football pitch, and a kilo has a surface area of a million square metres.