Deleting Specific User Data in Loki

How should I go about setting up my Grafana Loki system so that I can delete logs containing sensitive content from a specific user? This is to support user’s being able to request for their information to be deleted from the system. While there is support in Loki for deletion, it looks like I can’t specify a filter, and so if I don’t have a label that specifically specifies which data I want to delete, then I’m out of luck. From what I’ve read, you’re not supposed to create labels that have a large number of values (for instance a label that stores a user_id), so I don’t think that’s the right approach. Currently the user_id is encoded in the log values as json, and I extract it with json filtering stuff when querying my data.