Here are instructions on how to enable custom field and event based read receipts to reduce 'private comment clutter'. This will disable private comment read receipts and enable custom ticket field based read receipts.
In order to enable or disable custom ticket fields, please replace the MY-ZENDESK-SUBDOMAIN with your Zendesk subdomain. e.g. mysubdomain.zendesk.com where mysubdomain is what appears when you login to Zendesk.
If you disable this feature and would like to remove the custom field, please make sure you DISABLE the custom field instead of deleting it in case you would like to activate this feature again.
If you have any questions, please contact support.