Hey there. I was just reading about this Borax soap. First, is this the Borax that you buy in the grocery store that is considered "Mule Team", the stuff you use to boost your laundry detergent? Is this the same stuff? If so, do you have to rinse with vit c powder? I do not have any at this time, don't when I will be able to buy some. Can you use plain water to rinse with>?