Use an ordinary dishwashing detergent like Palmolive or baby shampoo in
a hose end sprayer [you should thin it with water] so you apply about a
drop or two per sq ft.

Avoid degreasers like [Shucks- the name of the common one that begins
with a D that turn debris to concrete] or shiners like Joy; lemon is
ok.

I tested this on clay; much to our surprise, when the prof tested for
softness, it lasted the entire growing season!!
This is a lost less detergent that youd eat if you wash dishes by hand

Mulch with straw [it looks nicer chewed a bit with a lawnmower] Some
feed stores will let you collect the stuff left over from below` the
bales for free. Ask