You have put the work in and now you can Smell the spoils of your labor...
Reasons your gear starts to stink:
Bacteria.
(Staph, MRSA, Strep & Yeast)
How to avaoid bacteria on your gear:
Shower thoroughly after every practice and match.
Don't share gear.
Allow your gear to air dry.
Wash after each use.
I know with life getting busy between school, practice & life, washing gear every time isn't always an option.
In this case get yourself some gear spray!!!
This can help keep the funk to a minimum until you can wash your gear.
Here is a great recipe to make your own.
https://diynatural.com/deodorizer-spray-sports-equipment/

You can also buy some on Amazon or at your local sports store.
https://a.co/d/2obplvX
Now to get to it...
Washing your headgear:

First things first, you want to prepare a cleaning solution.
Fill a small bowl with water and mix in laundry detergent.
You can also add a bit of white vinegar, which will help to eliminate odor.

Dampen a clean cloth with the detergent mixture and use it to wipe the outside of headgear. 
Pay extra attention to the forehead area as sweat tends to accumulate there.

Allow the headgear to dry completely before wearing it again.

As simple as that...
With any suggestions we make please check the ingredients and make sure you aren't sensetive or allergic to it. If any irritation occurs stop use immediately.
Meghan Melena