The first person to grab a trash bag after the party just became the host. Nobody voted.

Authority gets handed out far less often than it gets picked up. The person who starts cleaning changes the room, because now there is something to join. No title arrives first, and nobody announces it. It just becomes obvious who decided the night was theirs to take care of.

Look for the unglamorous job nobody has claimed this week and start it without a speech. Stacking chairs, carrying the cooler, wiping the counter. People tend to fall in beside you within a minute, and that is the whole mechanism.