It took some doing, but I got a package worked out that will passably simulate NPCs showering. Including undressing, showering, occasionally dropping the soap, then redressing when done.
Kicker is, the way I want to do this for best effect, is going to require a separate package for each NPC in the tunnels. That means ten packages I have to run up. This is going to take a little while.
On the up side, once done, v5.2 should be about ready for upload.