I am going to use Sweet n Low for snow. I have done the research, and nobody seems to have problems with it. However, would I apply hairspray or diluted white glue to the dio first to make the snow stick?

I assume that I would seal it with the hairspray afterwards.

HoneStly? the thought of using a food product like that always makes me think of bugs down the line. Personally, i'd just suck it up and buy some snow from Woodlands Scenics, mix some of it up with some plain white elmers glue, and there you have it, instant snow.

Better yet, heres a link for MAKING SNOW.

ACTUALLY, bugs won't touch sweet n' low because it's actually a chemical and not a natural food product so your safe to use it.

Suggest you try it on some scrap wood or plastic and see what happens. While the stuff isn't actually food (it's saccharine powder), it is designed to dissolve in water, so it may be affected by any water based glue or sprayed fixative. You also might want to leave it out for a while to see if it is affected long-term by water vapor (that's why I advise against using anything chemically reactive on a model or diorama, like baking soda or cleansers--they can absorb humidity from the air and discolor over time). And I discourage using anything that creepy crawlies might recognize as food, after I had weevils got into a diorama base covered with Celluclay and white glue. Now I use Durham's Water Putty for ground cover.