I buy it. I'm not really into meditation, but am deep thinking/reflection.

I found I got by far the most intense deep thinking sessions while mowing the lawn with a push mower. It was a large-ish yard, took around an hour. It's boring, monotonous, requires no thought. Keeps your hands occupied so you won't be tempted to 'check something real quick'. And lastly, loud enough to block any other sounds that could make your mind drift(sirens, birds, dogs barking, etc).