In Genesis 18:23-33, Avraham pleads with God to spare Sedom from the destruction it had earned through its wicked institutionalized cruelty. Eventually, Avraham extracts an agreement from God that the presence of even ten "צדיקים" - righteous people in the city would be enough to prevent its destruction. Unfortunately, even ten such people were not to be found, and the destruction proceeded on schedule.
I'm wondering what individuals would have had to do to qualify as one of these "righteous people." Would it be enough to personally abstain from participation in Sedom's system of oppresssion? Would ten people speaking out in favor of Avraham-style kindness and against Sedomite protectionism have been sufficient to protect the city? Would there have to be a demonstrable impact on Sedomite society from their speech, or would protests falling on deaf ears be sufficient? Or would God only save Sedom in the merit of ten people taking some sort of action beyond speech to bring about reform?