You should never store a dirty firearm. They should be cleaned after every use, especially if you're firing ammunition with corrosive primers. It's not absolute necessity that you clean them every single time - and many people don't - but it's good practice, especially for a firearm which you may be using to defend yourself with.
As often as you can.
A firearm should be cleaned every time it is fired, or once every two weeks in storage.
You should make sure that its in a clean place but you should clean it every few days
When possible, clean from the chamber to the muzzle. Due to the design of some firearms, this may be difficult or impossible. Cleaning in that fashion will push fouling/ carbon OUT of the gun, away from the working parts.
You should clean your Clarinet every time you play in it.
You should clean it everyday that you use it.
you should really clean your horses stall from 3-6 days of the week.
Ask a gunshop for help.
When you have a spa used by the public you want to drain it often. The water in the spa should always be clear and clean.
Once a month
once a week.