Snowballed is when you cum in someones mouth and instead of swallowing it they share it (mouth to mouth) with you or someone else.
As far as taste goes, if you eat shellfish it may obtain a slightly bitter twang to it, lots of red meat can give it a more hardier taste (those who like a heavy taste of come like this flavor ), white meats and lots of fruits and non-deep green leaves (iceberg, romain etc) keeps the flavor mild.
My wife and I have experimented with this over many years.