To help with Elasticsearch development, Archivematica comes with a plugin for Elasticsearch, called Elasticsearch Head, that provides a web application for browsing and administering Elasticsearch data. It can be accessed at http://your.host.name:9200/_plugin/head/.
Elasticsearch Head will allow you to delete an index, if need be.
The only way to limit access to ElasticSearch, currently, is using your server's firewall configuration. You'll likely want to configure your server's firewall to limit access to ElasticSearch's TCP/IP port (9200). It is recommended to only allow access by 127.0.0.1 (the server itself) and the IPs of any other servers or workstations that should be able to access it.