Any kind of an allergy can be very hazardous to individuals coming into contact with the allergens, i.e., peanuts, tree nuts, etc. The problem we have is we really do not know what individuals are sensitive to a particular allergen. I have a violent allergy to room freshener sprays -- I don't know if you would call it anaphyalactic shock, but need medical treatment immediately. Several years after a couple of instances with room freshener sprays, I was also diagnosed as having adult onset asthma. So for those reasons, in this household we have no air freshener sprays or solids, and for 30+ years, my employer would not allow them either directly in our office, or in adjacent condominium offices which he owned. From personal experience, I would never want to cause anyone the distress that occurs by coming in contact with the allergens to which one might be sensitive -- it doesn't feel very well. So, ladies, I don't know too much about making pin cushions, but rice is a nice, weighty grain. Just consider this, someone who's allergic to peanuts or tree nuts (and allergies to both can be present) even if what you're making only comes into contact with walnut shells, a serious allergic reaction can occur. So, either don't use walnut shells or make absolutely certain warning labels are present!