The shaving brush is probably the most neglected piece of grooming equipment in your bathroom. You probably dip it in the mug of water you used for your shave, remove visible lather and leave it alone.
In case you haven't noticed, your shaving brush is basically animal hair. Unless you're using a cheap nylon-hair brush. Anyway, by not thoroughly cleaning your brush, you're doing two things -
1. Applying chemicals from your last shave onto your face
2. Reducing the life of your brush.
Your brush exists to work with shaving cream and hot water to create an awesome lather to shave on. To get started, rinse your brush, root to tip (you'll find some old cream-good in the root. hang it out upside down in your shaving brush stand to drip-dry the leftover water in the bundle of hair that is your brush. If you don't have a stand ( I don't), put it in sunlight.
Putting it inside your bathroom cabinet immediately after a shave may cause mildew - it IS natural hair.
Cleaning the Shaving Brush: Inventory
A bit of vinegar (a pinch)
Detergent powder (another pinch)
A glass of water
Step 1: Cleaning your shaving brush
Rinse your brush under running water.
Step 2: Lather up the brush
Now rub in the detergent like a shampoo into the hairs of your brush.
Step 3: Soak
Put the soaped up brush inside the glass of water to soak for a minute.
Step 4:Rinse and repeat
Wash the brush again, removing all lather.
Step 5: Vinegar
Put the brush back in the glass, with clean water. Put in a good-sized pinch of vinegar. Let the brush soak in the vinegar water for a minute. Stir it a bit now and then
Step 6: Rinse and shine
Rinse out the brush.
I advise soaking the brush in water to soak out any residue + a bit more running water.
Now air out the brush - everyone can afford sunlight.
When should you clean the brush?
Hard water requires you to clean the brush more often. So does the use of shaving cream over soap (faster residue build-up). It also depends on how efficiently you clean out your brush when after you shave.
Casual rinsers should get the vinegar and detergent out when they notice any build-up near the brush - and this also depends on how often you shave.