This will make your life easier... Guaranteed!!!
I tried that Iron-Out stuff (http://www.superironout.com) that was recommended to get white pants clean. The stuff works so great it's unbelievable! No scrubbing. No pre-treating. No damaging BLEACH! Just soak in hot water!
First: You may want to run the pants through a regular wash first to get off any loose clay, or just get them wet by soaking them in the sink or on the back porch with a hose...
Then, pour some in 5-gallon bucket then add enough hot water to cover pants add a little detergent to the mix too. Add pants, pour a little more Iron-Out in on top and use a broom stick to move around. The stuff stinks a bit - like sulphur, so move it to the porch or garage ASAP! After a while ALL the stains just disappear! After they soak for an hour or more, just wash as normal.
I couldn't find anywhere locally, so I just ordered it on amazon.com
http://www.amazon.com/Summit-B...id=1331654378&sr=8-3You will not believe it! My son's pants that's he's wore in over 100 - 200 games look brand new! EVERY stain is completely gone... Even the ones that were over 1 year old... It also doesn't discolor braids or piping! I'm shocked and very happy!
-Good Luck!