I was in jachymov last April may for the second time and planning to return in April 2011. After 3 weeks of treatments, the results were the same as in previous years: It took six weeks before any noticeable improvement and lasting for about 10 months. From the patients I've met(some have been going for treatments for 15 years) the degree of result depended also on one's lifestyle/diet and mental outlook. My fist time I experienced some serious flares after the treatments, and much less after my second time.
Good luck in January. I suggest you bring things that will keep you occupied and brush up on German. Give my best to Dr. Jindrich. He speaks good English.
