Silver Plating of Glass Christmas Tree Decorations

Does anyone know how to silver coat decorative glass objects? I have a friend with a small jewelry shop located in a small town in the rainforest hinterland behind Cairns. He is in his seventies and has forgotten his old hungarian formula for silvering glass objects. Last time he tried to formulate the mixture of silver nitrate, water, trace of sugar and ammonium under a flame the mixture exploded in his face. You will recall your old chemistry days when silver nitrate stains were almost impossible to remove from finger tips. Jet black face for weeks.

Any advice will be welcome,

I am relying on my old memory but, I do believe we painted non-metallic objects with aluminum paint before plating them. Anyway it's worth a try.