I think you'll find that attendance at confession is on the endangered list. Haven't seen confessions listed for years, although its always possible to request it.
As for penances, no forgiveness without a firm purpose of amendment. That means, saying sorry, meaning it and resolving not to do it again. And then making it right.
So, for lazy men, chores would be an excellent idea, for those with sharp tongues, a period of silence and for the who won't engage an instruction to converse for at least a half hour every day.
For those who spend too much on their hobbies a financial penalty to be paid to their wives and for know alls an instruction to say three times every day
'Yes, dear, you are quite right.' :D