Sadly, the best one is - at least one person has to be the designated brewer (aka - the sober guy)
Also, have everyone get their equipment sanitized ahead of time. Designated brewer also should be keeping an eye out for a lull in the activitiy and offering new and exciting tasks for people to do. "So, guys, looking a bit well rested. Want to try and practice for the Olympic 'Grains Out' team?"