I'm a wildlife biologist, so I cannot address whether the commercial sticker-spreaders to which you're referring are even labeled for legal and safe use in residential or non-ag settings. I strongly recommend reading the label on those carefully before purchasing or applying.
As to using pepper or other irritants as a deterrent to herbivory - Reapplication will still be needed occasionally because UV light also degrades surface-applied products and because animals can easily habituate (i.e., learn to ignore) to smells and tastes if the underlying plant material is still food they recognize. If you decide to manage herbivory with deterrent tactics, rather than exclusion (i.e., fencing or caging), then I would advise switching among products (i.e., smells and flavors) fairly frequently (4-6 weeks?) to avoid habituation.