Hard water, lime deposits, scum…Vinegar!
Stuff a paper towel in faucet and pour vinegar on it. Leave on until vinegar dissolves all the junk. Wipe away. Now if you have the kind of faucet that you can’t stuff a paper towel into, just grab a plastic sandwich bag, or a plastic bag from your bread, or veggies. Wrap a paper towel around the end of nozzle and pour vinegar onto it and cover it with plastic and a rubber band to hold in place. A hair tie or hair clip can work too. This works for the end of a shower head that gets clogged up with ick. Vinegar is a simple and inexpensive way to clean. Happy cleaning!