In my practice and teaching, there is -No- pain taught in any Aikido technique, ever. From day one. Successfully. When properly understood, it isn't that difficult to teach this, even from a purely practical standpoint, but it is more rare, and it is far more sophisticated than simply teaching mechanics and Aiki-style jujitsu waza.
While I can see this in some techniques it doesn't sound right for all. How can a nikkyo not hurt? Sankyo? Hijishime?