Is there a way to hide OOB Email Templates?

My organization is going to create a whole set of templates for our users. 

We don't want users to create assets from scratch, using the blank templates that are provided by Eloqua (see picture attached) 

We would like to hide or delete the blank templates provided by Eloqua.

If it is not possible to delete or hide them, is it possible to freeze them, so they cannot be used ?

How can this be done?