Curious to hear what you all use to clean the dirt and grime from your well loved fretboards (particularly those that are lighter colored). I've got a few ukes with light fretboards (maple, light walnut, purple heart) and while I definitely like how the patina changes as it ages, I also want to be able to get some of that fingerprint dirt off when I change strings. I've used a tiny bit of lemon oil and that hasn't removed dirt well from the maple - better to help buff out marks on my soft wood tops.