It never hurts to inject a bit of humor once in a while.

A variation of this device would be in the medical area where an old person is put into a booth and with the usual flash of light, emerges as a teen-ager, a two year old, or Superman minus the uniform. Alternately, in lieu of committng suicide, someone could turn himself into a useful object like a leather suitcase, several dozen fur lined gloves, or a large quantty of pork chops.

Scotty, beam me up!

I've often thought it would be a fun plot for a book if you had a sort-of Midas glove that you could put on and while you touched something it would get younger.

People, cars, etc. Tires would un-wear-out, rust would disappear, dents would pop-out. Gray hair would turn color, wrinkles would disappear, mid-lines would shrink.

The plot would have to have an antagonist that steals it or something.