In the olden days it was IRC. Already then it was about controlling yourself. Whether you would get distracted or not. If you want to get into the zone, it's up to you how to do that. If you have an IRC or Slack window on the side to let you get distracted is your call.
Were you using IRC as your corporate messaging solution, because that's what slack is? İf people send you a message they expect a timely if not instant response. Their work depends on you.