Hi! Here are some tips from Apartment Therapy
1. Salt and Vinegar. Make a paste starting with a 1/2 tablespoon of salt and add in enough white vinegar to create a paste. Rub this on the residue left behind by the scummy water. Let it sit for 10 minutes and then wipe off with sponge or bottle brush.
2. Alka Seltzer. This is our go-to for cleaning a vase that we can’t fit our hand or a sponge into. Fill the vase with hot water and then drop in one or two tablets and let them do the dirty work.
3. Baking Soda and Vinegar. This is a similar approach to number 2, but fill the vase with warm water, pour in a tablespoon of baking soda (more if it’s a larger vase) and pour in white vinegar. It should fizz and eat away at the residue that’s built up. This is especially good for mineral deposits that don’t come off with scrubbing.
Denture tablets and warm water. Leave overnight, rinse well.
I wash mine by hand in mild soapy water.
Baking soda and vinegar works best for me.
Hope this Helps! Jeremy - https://do-daddy.com
My mom used to use denture cleaner and allow it to soak. Good luck!