Note: be sure to rinse collards thoroughly before using. Remove any thick stems and tear or chop leaves into strips. Cook bacon in a skillet until the fat renders and bacon becomes translucent. Place bacon, with its drippings, into the bottom of the crock pot. Add the greens, ham hock, salt, pepper, and water into crock pot. Cover and cook on low for 6 hours or on high for 3 hours. Remove ham hock, discard skin and shred meat, returning meat to crock pot. Serve greens with minced onion, vinegar and Tabasco, if desired.