Hi Erin. Try baking soda paste (mix water into baking soda a little at a time until it looks like tooth paste.) Leave it on for a little while and then scrub with an old tooth brush. If that doesn't work, you can cover the fixtures with the paste and then put vinegar into a plastic bag and pull it onto the fixture. Wrap it with rubber bands and leave it for an hour or so. Go back and scrub and rinse off. That should work. Then try sealing the fixtures with an exterior sealant, which should reduce the corrosion or possibly even stop it from recurring.
Hi Erin. I would put vinegar in a plastic bag and then use a rubber band to hold it on the shower head. Check on it in 10 minutes and use a tooth brush to scrub it off. Good Luck!
Thank you so much for the tips! I’ll try!!