JC, I never even thought of adding sugar to sauerkraut! But, the rinsing is a necessity, IMHO!
My mom said if you sprinkled a little sugar on it, it would brown better and not be too sour. (she told me the same thing about browning when frying country ham!) I wish she had taught me how to make HER dumplings! She didn’t measure and she made the very best dumplings. Now I can make dumplings, but not like mama’s.