Delete all data from apache solr core

Question

I have apache solr setup(version 8.9) in windows system(standalone version), import and search functionality is working fine, however the delete all(complete cleanup) functionality seems to be not accurate.

i delete the data using below command(tried with both url and solr UI using request handler /update), its returning the success message.

https://systemaName:8984/solr/app-core/update?{"delete":{"query":"*:*"}}&commit=true

but when i actually check the core/data folder size still shows 6GB, same will be displayed in the dashboard

How to reset/Delete complete data in apache solr core, so that we can import data from scratch.