I should perhaps explain what I'm trying to do.  The idea is not to create dancers ready to graduate (obviously), nor even to get them part way down the road.  The aim is to give contra dancers a feel for what square dancing is like at its best.  The flow. the satisfaction of meeting the caller's challenge, the surprise of the resolution.  To do this dancers do not need to have moves ingrained into them, but to have enough that with additional cues and aide memoires, and assistance from angels, they don't break down (or noticeably slow down).

My target is all the Mainstream moves, excluding Allemand Thar and related plus a few outliers like Zoom.  I will be teaching them in structured sections (NOT the same as the recommended teaching order), so if I don't get through them all then that's fine.

I have tested this approach already, with one contra dancer with no MWSD experience, four angels and three relatively poor MS dancers.  We managed to get through the entire program (excluding Thar etc) in just over an hour, and had 30 minutes fun dancing.  

It's still a big ask, but there are many things that can be done to help.  There's nothing wrong with calling "Wheel & Deal, that's Left hand couple step forward, everyone pivot round the inside person" which can be done quickly enough to maintain the flow.

I perhaps have an advantage doing it in the UK.  With all due respect to all the wonderful American contra dancers I have met, danced with and called for, UK contra dancers are far more used to dancing patter squares, and to the various formations that are found in MWSD.

Finally, yes Tom you have identified my biggest concern.  Despite the workshop being marked as advanced, and the requirements clearly specifying the dance experience necessary, you can guarantee that someone will turn up who is so bad that they will mess an entire square up.    That is, however, little different from what I at times encounter at club nights, and there are numerous ways of dealing with it.

I'll let you know how I get on!

Kindest regards

Jeremy