moneroblackball.com provides a list of known spent outputs that you can import into your wallet (with
mark_output_spent <filename> add, got renamed after the site was published).
One of the sets comes from the transactions that pools report when they pay out to miners. Is there any value in creating a script that generates this data from public Wownero pools and publishing the database? It doesn’t seem like it would be too difficult, but based on the popularity and last update of the Monero database, I’m not sure about its usefulness.