Milky = oil/water mix. Usually. If it has been sitting for a week or two, the mixture should have separated.
Possibly the bubbling of a water-lift would produce enough mixing action...
Yesterday, mine put out a cup or so of black gobby oil on startup
And thereafter left a tiny but discernible sheen on the water. Conditions were dead calm, so the oil spread out in a perfect semi-circle, leaving no doubt as to who pooped it out.
I'm sure that the black oil thing never happened before, but that sort of sheen would only be visible in very calm conditions. This was the first startup with the new exhaust system. It ran for a while last week with an obstructed exhaust.