for dirt and mud, simple green and garden hose has worked well. CX, MTB, Road = all same
for grease, a degreaser spray (like wd40) followed by simple green and garden hose - clean

of course, "clean" is relative. My clean could be someone else's dirty!
I know a couple guys whose bikes are immaculate. If my chain and cogset are silver, i'm happy

oops, just realized this is 50+ area. Well, this works well for us younger folks.