How long does it takes for ECS network interface to be fully removed?

I have an ECS Fargate service with a security group associated. This security group is only used by the Fargate service. If I decided to delete the service and the security group I'm having an error deleting the security group saying that the security group has some dependant objects. I get that this is due to the network interface created by the ECS service. What I would like to understand is how long it takes to AWS/ECS to clean these network interfaces after the services are deleted? I've tried to add a waiter after I delete the service waiting for the network interface to be gone but it is too variable and sometimes it can take more than 12 min!! Do I really need to wait until this network interface is gone to delete the security group? Is there another resource I can check to know that I can delete the security group? Is there a way to predict/make faster the deletion of the internal network interfaces created by ECS? It is quite annoying not having control over this.