Yeah, at the end of KoS when Cel was caught out giving Branwyn's Tears to mortals, he was meant to spend a year covered in the stuff and it was meant to have driven him crazy-go-nuts and he was last yelling that he was gonna fuck Merry...but I'm going to write that off as the oil talking.

Though, really, a year covered in horny-oil? He might get fed up with his hand, but dude, I don't think it'd make people go that crazy-go-nuts.

Then again, the idea that he'd make good on his promise and then have her executed does has its appeal.