What we do is, we give him some food to stop his barking. Open the chain let him free.
The dog will wander sometime and then he will find a corner to take rest.
Here the dog is our mind.
Give him some food, means thoughts. Let them come; don't try to stop the thoughts by anything.
Mind will wander and after sometime, will come back to the meditated state. It may be a single second in 20–30 mins duration.
Once we release the chain, dog start doing his natural behavior.
That's the key time where dog is in mode to learn new things.
It is slow but verified process. Don't care if it is wandering in thoughts for some days.
It will definitely find the corner to take rest.