Store bought butter milk and real butter milk are different, store read side panel it is made with yoghurt culture, farm butter milk is the left over stuff after making butter basically defatted milk (skim milk). The pre butter farm buttermilk milk is one spin separated cream we do this because trying to make butter from whole milk wastes space in churner. Milk even whole raw jerset milk is less than 20 percent by volume, when fist spin separation is done the volume 4 gallons turns into about 1/2 quart of cream, the reason we only do one spin is other wise milk tastes like water and no one will drink it. We wait till we get about 1 gallon of cream for us that is one day of milking. Then cream, ice cold goes into a mixing tube and whisked at high speed for 5-7 min the butter is then a solid and the liquid remains are poured into pail, then butter is washed with water also put into same pail. What’s in pail is butter milk. Use it to transition piglets at weaning to solid food or to big hogs as a treat. Not even the cat wiLl drink it, it likes suits directly from the teats (hand milk )
As for best cbrn mask best thing is glasses with thin wire as that cam be bent in to create seal, it’s not perfect but it is better than no mask. To test get a scent oil at mask place put it on tighten and then break capsule (outside away from areas you use)
If this does not work for you get a silicone half face mask and go to a scuba dive shop to try different goggles that can have prescibtions put in they don’t all fit the same so it is like shoes try and find best fit. Look online first to find best deal so you don’t get ripped off.
Another trick is if you can see with magnify plastic leans like credit card is to put one onto cbrn mask on face plate, if so get used to walking as it throws perception off. The already confined viewing area will be further reduced so keep your head on a swivel expecially up as more than one time I have found myself sitting on my butt after walking full speed into something that has hit the crown on my head that I didn’t see.