Do you know Rocky's life situation?
Was he a kennel dog?
Was he crated all day long?
You aren't training a puppy, which BTW, is a fairly speedy process.
This is an adult dog that has learned habits that will take time to break.
That is life and it won't happen overnight.
He may have spent 2 year learning these haibts.
Give him time.
Personally, when I get a rescue dog in, and they have accidents in my house… I clean them up. I tell them know.. but in no way to I scold them to hurt their feelers when I am first evaluating them.
I do take them outside to potty with other dogs and praise them for going potty.
If they still have accidents a week or two into my home, I will let [with my assistance of course] them sniff their own stuff…. AND tell them know.
That has never failed to work.
Basenjis DO pick things up quickly... but using harsh words from the get-go may not work with a dog that has had a less than stellar home-life.