Dryfasting plus breathwork will rapidly increase your frequency. Of course it increases healing effectiveness. It can greatly charge your spirit to be stronger in the fast. Wim hof method, Dr. Joe Dispenza. There all just breathing deeply. Increasing the oxygen content. That raises energy and frequency. If you do this strongly during a dryfast you can forcefully pull up stuck emotions. You can literally keep breathing deeper and deeper until you feel your body begins to vibrate with energy. Just don’t over do it, you don’t want to raise your frequency too high too fast during a dryfast. It will put a lot of pressure on your vital life force/organs having not been used to the energy.
Wimhof is great for revving the system up but it is a major stressor to the body. If you’re going for a cold plunge or want to activate your system wim hof is great for that but when fasting your body needs mostly rest.
During a prolonged fast there will be periods of calm but the more you can put your body in a resting state the better and for that I use Butyeko breathing.
Again, not saying wim hof isn’t helpful. Advanced fasters who regularly use breathwork with their fasts might say it would be useful during those periods of heightened energy which periodically happens to some fasters but as a whole and especially for someone starting out, it might not help the fast.