Look up smart water products as well … thieves hate them as they are difficult to remove from skin & clothing . Plus they glow under UV light and can be traced back to the user as smartwater make the product unique to an individual purchaser . 30 years ago there used to be another product called" Repulse " an indelible bright red UV detectable dye that had the most toenail gut wrenching revolting stench I've ever come across … real smell & vomit stuff . It used to be in a small aerosol for use to spray on yourself if attacked by a rapists or muggers etc. The smell is evil and takes weeks to disappear . For one particular tool shop Barry & I set up an aerosol in an innocuous aluminium housing by a door so that if the door was forced a solenoid above the operating button was tripped to lock on and spray the contents of the aerosol at waist height till it was empty .