A 16-year-old Bachur in Bussiéres was doing something wrong, and R’ Gershon Zatzal yelled at him. That night, the Bachur went to sleep, and he had already said K'riyas Sh’ma Al HaMitta, when suddenly he heard a knock at his door. It was R' Gershon Zatzal telling him that he had made a Cheshbon HaNefesh, and had decided that he had done wrong by yelling at him. He was now asking Me'chila.
This Bachur became one of R' Gershon’s top Talmidim and a major M'zakeh HaRabim. He is now about 80 years old, and he says that he can’t forget this story. R' Gershon Zatzal once potched a Bachur, and the next day he called his Yeshiva together for a Shmuess. During the Shmuess, he apologized to the Bachur publicly for hitting him, and he said that Hashem had punished him, and his hand was full of pain all night long. This Bachur told me this story, which he cannot forget [and he loves R' Gershon Zatzal].
Someone once got angry at the Hanahala of Novardok, and he left the Yeshiva and went home. The next day, R' Gershon Zatzal made a special trip, to fall down at his doorstep to ask Me'chila. Needless to say, this brought the boy back to Yiddishkeit.
Being Mach'nia was a major Inyan in Novardok, and those who were into this Sugya were proud of their ability to be Mach'nia. Especially R' Gershon himself, and R' Ozer Schwartz Zatzal and R' Chaim Halperin Zatzal; they were all soft as butter, and they were very sincere [it wasn’t just a game to be “Yotzei” asking Me'chila]. They believed that Hachna'a brings all the Brachos, Yeshuos, and Refuos. I have seen first-hand the power of Hachna'a when I needed a Refua. Speaking softly and listening to others, being M'vater and giving in; not getting angry, and not answering back, tolerating a difficult Matzav; all these are forms of Hachna'a.
When something went wrong, the #1 form of Teshuva was exercising Hachna'a. R' Gershon could also be quite a Chevra'man.