both extracts out DOC, just that wet skimmate will drain out your salt water...that's y most prefer drier skimmate to reduce water lose....
even if the skimmate is dry, the DOC will be captured at the top of the foam, so it doesn't mean that drier skimmate will be less effective, it looks less but thicker... it think it is like normal shit and LAO SAI....both are all that's in your bowel, just that lao sai dehydrates a person....
PS: i am not tryin to be rude, just that i cannot find better comparison....