Yoshinkan dojo have a very easy answer for some of this...
We line up shite and uke facing each other.
Instructor says "kotite!"
Everyone on one side of the line moves left. The ones at the far left move to the front of their line.
Repeat, and rinse well afterward.
Ron (in my case rinse very well. I sweat like a demon, and the tobacco smell just pours out of my pores. EEEeeeewwww....)