Toilet cleaning is a regular part of cleaning, but how often do you clean the inside of the rim and the siphon jets? If you're like most homeowner, not often. I'll spare you all the details but you basically flush vinegar from your tank into the rim.
Skip the Harsh Cleaners: You Can Remove Rust with a Potato! The potato trick is so handy (and non-toxic!) and it isn't limited to cast iron — you can use it to remove rust from baking pans, knives, and other household tools. Tips from The Kitchn