I don't know if a person can still buy leaf polish or stuff to make them shine. But I remember seeing a product to spray on house plants... rubber trees, and philodendron especially to make the leaves beautiful and very shiny. In fact, I used it from time to time to just bring out the beauty of the plant.
Last week, I had a spray bottle of sugar water to use on my honeybees. I sat it down near my seedlings. Later on, I misted the seedlings, and my houseplants... I noticed after the fact that it was the sugar water... too late, but surely it wouldn't seriously hurt them.
I have the shiniest plants imaginable. They are very glossy! I don't imagine that plain granulated sugar dissolved in water would seriously hurt the plants. They may become dust magnets... but they sure are pretty!