I've been making different versions of those for almost 10 years now. One thing to mention, is to make SURE you wash them out thoroughly with detergent after the silicone is set well and before they are worn. This will remove the chemicals that leach out of the silicone when it is fresh.
They can also be washed in a machine in cold water -bonus!
I had never had a problem with anyone wearing these until last year, when one of my actors had a bad reaction to the gloves after he had worn them on his sweaty hands all night -so watch out for any skin irritation & remove promptly if that happens & wash your hands/arms with soap & water.
Most folks don't have any trouble wearing them though.
You can also imbed a wide variety of materials into the silicone, such as hair, cheesecloth, fake-nails, glitter.. etc
Good tutorial Allen!