Can is doing an awful lot of heaving lifting there.
Given that my sink cannot contain 20 gallons of water and that I do not even fill my sink full to do my dishes by hand, I cannot possibly be using 20 gallons of water to do my dishes when I do my dishes by hand.
Given that my sink cannot contain 20 gallons of water and that I do not even fill my sink full to do my dishes by hand, I cannot possibly be using 20 gallons of water to do my dishes when I do my dishes by hand.