Docker Cloud is running a BETA for Swarm mode -- this allows you to create a Docker Swarm in AWS and test out the early incarnation of the Docker Cloud Swarm support.
Once you've had a play you might want to clean things up and bring your AWS account back to its previous state. However, when you remove the Swarm cluster from Docker Cloud's UI you get a warning that you'll need to "directly access the swarm to terminate":
Terminating the EC2 instances in your AWS console is a no go -- they'll just spring back to life in a few minutes. You need to remove the CloudFormation template that Docker Cloud used to create all the resources needed to run the Swarm. This is easy enough
Go to the CloudFormation service area and locate the Docker for AWS template.
Select the template and the Delete Stack action.
Confirm deletion; it's going to rip out everything that it put in.
It may take a few minutes...
All cleaned up!