Start up the Intercom Respond widget being sure to clear previous user's conversations.

boot-intercom-respond.js

/**
 * Boots up Intercom (intercom.io). This should be run on page load
 * @param {String} APP_ID - Your Intercom app id
 * @param {Function} moment - moment.js
 * @param {Object} [user] - information about the logged in user
 */
startupIntercom(APP_ID, moment, user) {

  // basic settings for all users
  const intercomSettings = {
    app_id: APP_ID,
    custom_launcher_selector: '.js-intercom'
  };

  // Do an initial startup with just the basic settings.
  Intercom('boot', intercomSettings);

  // flush out any previous cookie before starting up to prevent seeing
  // other user's conversations on the same computer this can only be done properly
  // if 'boot' has already been triggered.
  //
  // if this was a single-page app then you could just run this by itself when a user logs out
  Intercom('shutdown');

  // add user specific settings
  if (user) {
      intercomSettings.user_id = user.id;
      intercomSettings.name = user.name;
      intercomSettings.email = user.email;
      intercomSettings.created_at = moment( user.created_at, 'YYYY-MM-DD HH:mm:ss').unix();
  }

  // start up the intercom client for real
  Intercom('boot', intercomSettings);
}

Lifesaver 👍