This is a tricky one. You could remove the "Data: View Data" permission from the Administrators group. Alternatively, you could remove the group from the Director application to stop them logging in the application. You need to bear in mind that as Administrators they have the permissions to change these settings back so if you want to prevent this then you'd need to create a second separate admin group just for managing user and group security permissions [and then obviously remove the appropriate rights from the first Administrators group].
Another option is to read and write the data using a client-side data store so that you don't need to copy it to the server landing area? You can turn off processor results so that none of the intermediate processing is visible in the UI. The downside of this approach is that you won't be able to run this as part of a job.