Interesting. I am definitely not a doctor. If you have medical advice to practice this technique, I would follow it.

I will say that I have been practicing mindfulness meditation for 7 years in various traditions and have never come across this technique. It also goes against the definition of mindfulness (paying attention to the present moment without judgement) as it is applying judgement to your thoughts.

I have experienced very difficult and dark periods of meditation when I was hard on myself for thinking, and learning to be very kind to myself in meditation was a huge step forward in my practice. Rather than “stop”, I say “thinking” to myself in a kind way.