I’ve had some success getting soured buttermilk smell/damp funky camper boy smell out of clothes with Woolite. Look for the version they make for washing machines now. It’s not too expensive, and a little goes a long way. Plus, it should be easy going on your yarns.
Chocolate milk and the knitting bag don't play well together
I’m thinking it’s going to take some enzymatic type stain remover/cleaner (and I think OxiClean is one of those) to break down the milk proteins to get the smell out.
I once spilled a cappuccino on the passenger side floor of my car…talk about a stiiiiiiiiinkyyyyyyyy smell for a long time, especially in the hot summer, icky! I don’t even recall what I did for it, I think just a lot of soaking and blotting, I didn’t have a steam vac at the time.
Here is a google search I did of “removing sour milk smell,” maybe that will give you some ideas. Do you have enough extra yarn to make a swatch you can test cleaners on to make sure they don’t harm your yarn?
http://www.google.com/search?hl=en&q=removing+sour+milk+smell
I was thinking Woolite, and I thought I had some left, but I didn’t, so that was plan A for the Walmart trip. I’m hoping to finish the tank top tonight, then I should have some of the yarn left over to swatch to test the enzyme cleaners. I’m going to buy a couple different ones today and see what works.