I wouldn't go as far to sat Chettawut's technique is painless, or complication free, I sure it depends on the individual, for me the worse pain (I ever felt) was right after surgery when the anesthesia wore off, and the first 2 weeks of dilating, I still remember feeling like I was going to puke when we finally went to using the first (actual) dilator, and I did puke in the clinic

.. everyone is different, but after the 2 weeks everything went downhill and became so much easier