Nick Hallale wrote:
Are there any schools/branches of Aikido that do this as part of training? Or is it generally thought of as madness that is left up to the individual?
yes, it's part of practice in Ki Society known as River (water) Misogi.
It's optional training. No one is required to do it.
Often down in early January as part of Kigami Biraki seminars.
You are taught some breathing techniques first before entering the cold water. Once you are out there as a group at around waist high ice cold water you all dunk as a group and while doing kiai's. The best way is actually finish with ki breathing and meditation back at the dojo to warm up (assumming it's close by) and then have a hot breakfast ;-)
That's what you can do in Seattle using a lake fed by ice cold mountain water. In New Jersey or Kansas they actually make a large hole in the ice covered river or lake and do it. In Canada .... ?
In Texas, like Hawaii, the best we can do is splash you with a big bucket of ice water
just not quite the same.