Do I set the 

CLEARML_FILES_HOST

 to the end point instead of an s3 bucket?

Yes you are right this is not straight forward:
CLEARML_FILES_HOST=" s3://minio_ip:9001 "
Notice you must specify "port" , this is how it knows this is not AWS. I would avoid using an IP and register the minio as a host on your local DNS / firewall. This way if you change the IP the links will not get broken 🙂