Don't bother with silicone. Just put rice into a balloon and presto there is a stress ball!!
Don't use silicone. Use cornstarch or dough:http://www.organichealthblog.com/2008/make-your-very-own-stress-ball/P'rfesser
. Great answer! I need to start thinking outside the box more often. ;)
. Silicone gel. Silicone grease. Breast implants.
Can't you get a tube of silicone caulk from the hardware store and squirt it into a balloon?