Cause the oil mist won't have enough dwell time in the bucket to actually settle out.Any reason why you would do that over a larger vent in the top of the bucket?
A muffler (multiples) may help. But really what @formernuke needs is a larger bucket with baffles in it so the high velocity air has enough room to expand and slow down. A smaller volume of purge would make this bucket adequate, but if they can't shrink the purge volume or purge rate then use a larger receiving bucket. Or two buckets. Then the ratio of purge air to bucket volume goes way down. What you're trying to do here is take a small high velocity flow rate in the purge tubing and dial it way back to a large low velocity rate where gravity has enough time to let the mist settle out.