Howdy. I'm looking for advice on cleaning and preserving a bowl Bob Stackhouse turned from a single piece of Thailand teak. Backstory: we recently inherited some kitchenware and cookbooks from an aunt, including what looked like a salad bowl made from what appeared to be walnut. I was amazed when I found Stackhouse's signature on the bottom. My aunt evidently used it regularly as a salad bowl. The inside has darkened and the inner and outer surfaces feel gummy and sticky to the touch, so I assume she rubbed it occasionally with olive oil or canola. Can anyone suggest how I should clean it and what would be a good finish to apply afterward? Thanks!