Huh? What?

Care to explain?
I think I get it though - you mean controlled breathing to relax yourself?
I had success with it - I would be able to control my breathing and automatically stop my anxiety from happening. Because anxiety and deep/slow breaths are like oil and water, they just don't mix!
The thing is, I found it to be too much work (I used to get anxious a lot during the day and having to work on controlling my breathing just took to much effort/energy from my part because I had to do it very often during the day.) It works - it just takes too much work to do, imo.
What I found that works best (so far), is cognative behaviour therapy excercices before confronting an anxious situation. It makes me think
straight and realistically... which lasts a lot longer and works faster than controlled breathing. But that's just my opinion and experience on those things.