I am a Daddy and have used corner time and diapers effectively to punish my adult baby boy or girl. It works this way
if they are to be punished first I spank them across my knee then I diaper them. A disposable diaper, plastic panties, a frilly ruffled panties and a t-shirt is all they are allowed and then it is corner time.
I will either have them stand facing the wall side by side with their thumbs in their mouth sucking and drooling and their hand on their hand or with a pacifier. We also have a time out chair that is effective after a spanking. A small child's chair where they sit knees almost touching their chests.
No wiggling or fidgeting is allowed.