Viewing the Zdenko Domancic film, "Think About It" once more...I like the term 'building the immune system'...and the idea that the many different ways don't really matter...that they all take us to the same place...well-being.
Another 'way' I have tried that works very well is the balanced mineral bath or footbath...
...20 to 30 minutes in a one percent solution of Himalayan crystal salts (balanced mineral deposits left from ancient oceans), at 97 degrees.