Forogot to add when I stock up on laundry soap I buy the store brand in the plastic buckets, as it can be stored on the bottom of the store room and is immune to flooding. Plus after you use it, you have a free bucket, another barter item.
And don't throw away those empty plastic laundry soap bottles! There is still detergent in them. So fill them with water...slowly to avoid bubbles...and then mark them as "Wash Water". When/if water is scarce you can use them as...well...wash water for laundry by hand or other things that need washing.