[Alan Brinton]

Cleaning the recent model melodicas before selling is not a problem. Most sellers don’t do it. But, if you want to be conscientious, rinse the melodica out with water (with 1/3 white vinegar added if you like), blow it out well and let it dry, and clean the mouthpiece with a 50-50 mix of water and 3% isopropyl alcohol (the cheap stuff sold at drug stores). You could sell on eBay or try doing so on Craigslist (if you’re in the U.S.).