The problem with his ritual is that he lost the warm showers. Warm to hot showers have their own benefits like opening up the skin pores for better cleaning while cold water closes shrinks them. As he already realised once he gets a warm shower again he might not go back. I adopted cold showers for many years successfully with only very rare skips when I’m physically weak and ill. I just do a normal shower maybe with increasing heat and finish off cold.

As he describes correctly the effects are just awesome and I can’t skip it. The 3 minutes are not a necessity do as much as u feel comfortable your cold resistance increases each time. Fast deep breaths help but be very careful when switching from hot to cold in addition with deep breaths your body will collapse from hyperventilation quickly.