Dust, earth, and mud provide the theme for this opus, but, alas, it has a covert theme. It didn't have to be so; a bath would have cleaned it up. And 1 Across happens to be BATH. Why not link it to the theme?
I am glad the editors allowed THEFBI and INNYC. Such entries were verboten when I constructed Xwords B.C. (before computers).
It was interesting to see two meanings of keyboard in one puzzle [type and play piano]. Would a computer gamer be a "Keyboard player" and do PIANISTS "Work at a keyboard"?
I liked "Frosty's button, e.g."