Due to their tendency to reject and the fact that healing multiple piercings at one time is rather stressful on the body, most people choose to wear corset piercings temporarily, for a special occasion or event such as a tattoo convention. After the event is over, they remove the piercings and allow the holes to heal up. Since they were only in the skin for a couple of days, there usually isn't too much scarring as a result and the corset can be pierced again some weeks or months down the line.
If, however, you wish to have a corset piercing that is permanent, the first rule of thumb is NOT to use CBR jewelry. The pressure on the skin that the rings create, especially through movement and possible pulling from the ribbon used to connect the rings, are not conducive to healing and will most certainly cause the rings to migrate and reject.
Instead, what is known as slave barbells or doorknockers should be used, which are barbells with a ring attached to either or both ball ends. That way, when the ribbon is threaded through the rings, the tension is on the barbell, not the rings, which gives the piercings a better chance at healing without migration and rejection. There is always a risk, but at least the odds are in your favor.
Corset piercings should only be done by a highly skilled surface piercer and the client should have a high pain threshold, because this is not an easy piercing process to sit through.
Healing will take a minimum of 12 weeks.