PFAFFENHOFEN, WEST GERMANY — GOING FOR IT. ''Snort it up.'' The cry was directed at competitors in the fifth, and biggest, snuff-taking world championship. The rules were stringent. A sneeze meant disqualification. Not a crumb could be on face or beard. Heinrich Kugler of Unterbach, West Germany, was the winner. Christopher Columbus reported seeing snuff used in the New World, and seafarers brought the practice to Europe. It did not become popular until the mid-16th century. Devoted snuff users swear that the stuff keeps their heads clear and wards off runny noses and colds.