I bought Oxine a few months ago and it came with a free container of Citric Acid. I'm not going to use it and don't want to just throw it away and can't think of another use for it.
You can use it like a natural type of Lime Away. Mix it with baking soda to remove hard water deposits, etc. I use it to clean the bathroom and sometimes sprinkle a little in the dishwasher.
Kim