If you set up an event-level Slack integration, then silencing notifications for that one event is as simple as toggling the integration off.

Wait, what's an event-level Slack integration?

Event-level refers to the setup being a la carte — in other words, for a single event.

Whereas an organization-level configuration means that every event in the organization is governed by the integration.

To turn off an event-level Slack integration:

1. Go to the event page
2. Click into the Form tab
3. Enter the Integrations sub-tab
4. Toggle the integration Off

To turn off Slack notifications for a single event when you have an organization-level integration is possible but not yet DIY. Just shoot your Customer Support Specialist or CSM an email, and he/she will be able to suppress the event's Slack notifications.