OUTWhite Brite Laundry Whitener Powder, Stain Remover Detergent Booster for Clothes, 4 Pound 12 Ounce

I have a couple of shirts that are half white/half color. Would this be safe to use on those?

Will this combat yellowing from face and body oils on my "white" comforter?

Hi! Will this turn cream colored sweaters white? Bleach did not work.

For rusty/hard water, do you add more White Brite during the rinse cycle as well to keep the rust off of your whites?