There is a fairly lengthy mud scene in the 1943 movie "No Time for Love". It involves a female reporter played by Claudette Colbert photographing several men (including Fred MacMurray) working in a tunnel below the Hudson River. A somewhat low quality version of the movie was recently posted in six parts with the heavy action starting about 3:30 into part five when a wall collapses and a LOT of mud pours in. To me the best part comes soon after when they extricate the reporter and crawl through the mud (with some sneaky gropage going on ), but the scene continues to the end of the clip and a few seconds into part six. Oh to be an extra on THAT set!