Can you really keep feta for 3 months in a milk bath?

I'm not sure when that about.com article was written, but if it was posted less than about about 8 months ago, it may have plagarized The Culinarian: A Kitchen Desk Reference by Barbara Ann Kipfer. In that, Kipfer provides "Hints" after the description of what feta is (p. 224-225; you can view it on Google Books):

Consumers who dislike feta's salty taste may soak the cheese in fresh water to leach out some of the salt...Feta cheese is best when eaten fresh, so always check the date. If you will not be consuming it immediately, store feta cheese in a brine or milk bath in the refrigerator. The milk bath will reduce the saltiness and help keep the cheese moist and mild in flavor. Properly stored in brine or milk and refrigerated, feta cheese will last for up to three months. Feta cheese is not a candidate for freezing. Barrel-aged feta sold straight from the barrel may be wrapped in lightweight paper, then wrapped in a plastic bag or plastic wrap and stored in the refrigerator. Keep the feta in paper, even when the paper gets soggy from the cheese moisture.

Emphasis is mine to show you that the bit about the milk bath matches about.com's article word for word.

Since The Culinarian was published by Wiley & Sons, a reputable publisher that puts out a lot of textbooks and academic and trade journals, I would assume that it was properly fact-checked. Given that Kipfer talks about salt leaching out into regular water and the milk bath reducing the saltiness of the cheese, I would guess that there's a strong chance enough salt leaches into the milk bath to act as a preservative.

Take all this with a grain of salt, though (no pun intended); I've never tried keeping feta in a milk bath myself.

Just a note: You should not "store" feta in a milk bath. If you wish to reduce the saltiness, soak what you are going to immediately use in milk for a couple of hours prior to use. Otherwise you want to store feta in a brine solution, preferable 12-16% salt by weight. The recommendations of 1 pound of salt per gallon of water is a saturated brine and will increase the saltiness of your feta. On the other hand, if you want to store the feta for months that is likely the way to go, and then just do the soak in milk thing for what you are going to use. I make my own cheeses, including feta and it is quite amazing how much misinformation is available on the web.

I knew a Greek family back in the mid 1960s that introduced us to Feta. The dad bought it in bulk packed in brine. He advised my Mom to repack it in milk. It did not stay long. Never spoiled. Been doing that for decades. (Not buying in bulk). His cheese was creamy. Took me years to find 'creamy' feta. Similar to what we know as Bulgarian or French. Hope this helps with info.

I’m Greek and have eaten feta all my life. It is common practice for all Greek people to store their feta in milk once they bring it home from the shop, and in an airtight container, in the refrigerator. This does make the cheese creamier and less salty. It also preserves the cheese longer but definitely not as long as 3 months. You will be lucky to get 2 weeks maximum from this method. Feta cheese turns very quickly so it must be eaten as soon as possible. It does not freeze well.