You have to turn off the sc_local_db as well (=none).
There is nothing specific in the log that says it is working (though it is possible to turn on more verbose logging), but you shouldn't see any more cffs01.... checks every 10 minutes.
There is a way you can infer it though. If you look at http.log each request has a cattime="12345" in microseconds.
So if you get a cattime that is 39000 that is 39 milliseconds to do the categorization, which means it was a cloud lookup. If you get a cattime that is 200 it is less than a millisecond, it must be local cache. Basically 5-6 digit numbers are cloud and 2-3 digit numbers are local.
There are some websites (google is an unfortunate example) where caching is not possible, so every request will have a cattime > 20ms.
