I have an Apple Watch Series 2, and I had a similar issue with ghost scrolling a while back. My Watch has some slight damage on the Crown as well. What worked very well for me was applying isopropyl alcohol around the crown area and spinning it a bunch, then rinsing it with warm water as per Apple guidelines. If you have a sink that has a rinsing nozzle and can put out some higher pressure water, spraying that in the Crown area when rinsing may help as well. Good luck with your repair!
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