Don't try to make them smell good. Nothing will work.

Have you poured baking soda in them and let them sit with that for a whole weekend?

Try stuffing them with newspapers, this used to work for my sons soccer shoes

Odor is caused by bacteria.
Try Gold Bond medicated powder.

Baking soda has always worked for me

I did a job before I was walking up and down the deck all day and got the same problem, only thing to do is get a second pair, or if yours have turned two new pairs and alternate them daily

Need to have another pair and air those out a day or two.

Place a tea bag in each boot to absorb the odor.

Sometimes you just gotta get new boots.

Baking soda and green tea bags may help.

Make sure you're wearing good socks.

My socks reek a lot. But those are easily taken care of. You clean and change socks, boots and shoes should get similar treatment.

Buy a second pair, use a good foot powder and wear them every other day. Not perfect but it helps a lot.

Baking soda for the boots.
Talcum powder for your feet.

Put a bay leaf in each boot, your feet will still sweat but it will smell like soup!

stay off the cam.

I know ur gonna think this is a joke but buy Monkey Butt Powder. I ride a bike and that stuff is crazy good. Put it in boots---zero stink. On your butt and balls on long rides...no chafing or sweating. Get it at Walmart.