Use something like this:
mgmt_cli delete host --batch <full path to your csv file>
Of course, you will need to make sure your API server is configured properly, you will have to log in, publish after deletion, and log out.
Another piece of advice, deleting in bulks may take a long time. I would suggest breaking down your list of 10k into a group of around 500 IPs, so you would not experience a timeout with this.
Look for other examples of using a batch file with API, for example here: https://community.checkpoint.com/t5/Management/Trying-to-add-hosts-in-mgmt-cli-using-csv-file/td-p/7...