Stress balls can be made of many materials. Rice sealed in a material that is stretchy such as vinyl, is one type of materials that a stress ball is made of. Another way more complex stress balls are made is to inject a malleable material with foam or a rubbery gel substance.
It's not toxic, believe it or not!
No tennis balls are not toxic. Many people may think they are but that is not true.
As of June 2014 there is not a listed location that sells the growing gel balls for goldfish. Some local aquarium stores may carry them.
Silica gel is not edible because it is hard and tough. It also has other chemicals added to it that should not be eaten. The silica gel itself is not toxic.
No, it is a water based non toxic gel.
yes
No, while colorless silica gel is non-toxic, the dopants used as color moisture indicator in silica gel (such as cobalt (II) chloride) are carcinogens and are quite toxic.
stressbal
No, the rubber compound is not good for them. Tennis balls are toxic for any animals.
The benefits of using stress balls is that it relieves stress. You can use stress balls for many different things. Teachers use them in classrooms for students that have ADHD or Aspergers in order to focus their energy into something so that they can focus in the classroom.
Kinko's does not have custom labeled stress balls, however other companies do. Quality Logo Products has wide variety of private label stress balls available. Check out their website at: http://www.qualitylogoproducts.com/ball-stress.htm