Hello,
Well, yes there is, but it would probably take you just as long
Lists Indices:
curl -XGET http://localhost:9200/_cat/shards
Delete Indices
curl -XDELETE 'http://localhost:9200/name_of_index/'
Graylog Server Service might need to be restarted.
It probably doesn’t consider close indices, so you may need to open them up and recalculate the indexes again. I personally haven’t done that, but you could give it a try.