Cleaning Stained White Artificial Christmas Tree

Cleaning: Mix equal parts of peroxide and hot water in a spray bottle. Mist thoroughly and let stand for 5 minutes. Then spray again and wipe with white cloth. Removes nicotine stains and cardboard staining. May need to be repeated.
Preventing yellowing: Line box with white trash bag and put a box of refrigerator baking soda in box with tree.

what causes the white branches to turn yellow? could packing it using blue paper and wrapping it in a white sheet help or not?
thanks so much

I have same problem, just certain branches. Any good resolutions to this problem? Perhaps store in blue paper like wedding dresses?

I would try simple soaking in a vinegar bath and swishing......maybe add a little dish soap......bleach may yellow it, so I'd avoid that unless recommended by the maufacturer.......