We've had this problem, and ended up having to write it ourselves. There are a lot of patterns that identify data as potentially sensitive, and being able to redact this is part of something we've created.
It's open source and written in Go -- so you can see the types of data that we've identified as needing redaction:
https://github.com/replicatedhq/troubleshoot/blob/e42b7c3d77...