ames, there’s a story about the chofeitz chaim that a bochur was caught smoking on shabbos and they wanted to kick him out. the CC told them to send the guy to him first. when the guy came, the CC took his hand in his own and started crying “shabbos… heilige shabbos” (that’s: shabbos… holy shabbos) the bochur ended up staying and was never mechalel shabbos again.
i forgot who was repeating the story at a gathering i believe in Florida (either rabbi frand or rabbi krohn) and a guy came over to him afterward and introduced himself as that bochur