Forming AgCl from electroless Ag
I would recommend this patent which generates AgCl via the electrolytic chlorination of sheet silver, to quote:


  The present invention relates to a method for chlorination of silver materials in the forms of wire, thick film paste and metallic sheet/disc. The method is environmentally friendly since the process does not produce hazardous chemicals or flammable gas. The electrochemical setup includes position the electrode containing silver materials in the anode and a platinum wire at the cathode. A DC voltage supply between 1 to 5 volts oxidizes the silver surface which receives chloride from imidazolium chloride solution to produce silver chloride on silver wire, film or disc. The imidazolium chloride reagent can be in aqueous solution or polar organic solvents or naturally exists in ionic liquid form. The imidazolium radical cation decomposes to produce a stabilized organic radical and an imidazole molecule. The stabilized radical recombines to produce volatile organic compound that can be recovered by simple distillation. The chlorination reagent can be regenerated...


In place of platinum wire perhaps a diamond electrode.

Also, some pertinent comment from atomistry, to quote:


  The rose-red to purple-brown mixtures of silver subchloride and silver chloride are called by Carey Lea " photochlorides." They are formed by the interaction of colloidal silver and a suspension of silver chloride; by the action of organic reducers and of light on silver chloride; and by the electrolytic chlorination of sheet silver. The photochlorides are characterized by their great sensitiveness to light, blue light producing a blue coloration, and red light a red coloration. This action is reversible, the blue coloration being transformed into red by the action of red light, and so on. This phenomenon is inapplicable to the production of colour-photographs, for white light causes a darkening in colour.