Dishwashing fluids contain bleach and other harsh chemicals that can e.g. remove caked on tea residue from cups, something soap will not do without a lot of dir

Dishwashing fluids contain bleach and other harsh chemicals that can e.g. remove caked on tea residue from cups, something soap will not do without a lot of direct mechanical action. As a tea drinker, unless you are very fastidious, handwashing generally doesn't remove everything and a layer can build up in cups which needs standing in bleach every so often to clear out.