Mildew smell

So my son left his coat in his pack for a couple of months and now it has small black dots on it and smells like mildew. Lots of tips on the internet (vinegar, baking soda, diluted bleach, ammonia to name a few) of how to get rid of this smell, but nothing on any reputable sites. Does anyone know of anything that actually works to get rid of it?

Try a product called RID 'Z ODOR, it's a water soluble deodorizer. Gets rid of smoke and fire odor, pet odor, mildew and mold. You can buy this at a local commercial janitorial supply.

I have had great luck with a McNett product called Mirazyme, it has worked on smelly mildewed tents, stinky ski boot liners, and it even took the edge off a skunk sprayed dog. I keep a spray bottle around for smell emergencies. Just follow the directions on the label.

Wash it with soap and just a hint of bleach and then put it in the freezer for a few days. I've used this method and it works.