A rubber band probably would not work. There are published techniques where a suture is used to ligate the base of the keloid. Over time the keloid will lose its blood supply and fall off. These can take some time and requires multiple trips to a plastic surgeon's office. Further, without additional followup the keloid can recur. For this reason, the most frequently used options for keloid treatment are injections with steroids and subsequent surgical removal of the keloid. I hope this information is helpful.
Stephen Weber MD, FACS
Denver Facial Plastic Surgeon