Several things come to mind. Choice of metal, for one. Nickle allergies can raise hell with those sensitive to that metal, stainless steel is stainless because it is an alloy containing nickle. Other, non noble metals, can cause metal poisoning as well. That leaves the more tolerable metals ... gold, silver, titanium, a few safe alloys used in medical/dental usage. A homemade device using plastic points, such as the material used for carpet protection for chairs or stairs could be fashioned to provide the sensation of being pierced without the potential damage until the wearer decides how to further proceed. The plastic points can be sharpened or dulled with a nail file or Dremel tool to determine the depth of penetration, point spacing, sharpness, tolerance of pain or piercing or infection. Either a leather belt or doubled over fabric can be used for the belt. Such cilices can be used for differing periods, i.e. 24 hrs around the breasts, 48 hrs around the thighs. For Forum research purposes photos taken hourly of these in both locations is recommended for proper feedback and diagnosis. Make them tight. Purple globes come to mind. Also photos of the skin after removal. We anxiously await the results of your research!