I personally use this tool to identify stale DNS records for stevenpolley.net. All it does is grab all your zones, then loop through each zone. For each zone, it grabs each record and loops through each record. For each record, it checks DNS query analytics and then provides a report showing records and their query metrics. This can then be used to manually identify stale records and then perhaps take manual action afterwards. It does not make any changes to Cloudflare directly and only requires read access.

The entire project makes use of only the Go standard library, no third party dependencies at all. Also CF's own golang SDK is missing features to retrieve analytics for individual DNS records.