Would it make sense to schedule a series of training classes that would have stations, with a known amount of time for speaking, and then at an agreed upon time, the dust collectors come on and the hands on portion starts for some time.
For example, to elaborate a bit on @AlexRhodes I could see several stations with the spoken portion going on at once. Then if you're finished with the spoken portion before the time is up, that station waits until it's time to "go loud" with the machines on. Obviously, we would have to figure out timing, and make sure the teachers can be heard.
Fictional Class time starts at 11a. I don't know the exact timing for demonstration or the spoken portion, but it should be able to get a general schedule.
11:00a-11:30a - Safety/Basics
Instructor 1 - Table Saws
Instructor 2 - Jointer/Planer
11:31a - 12:00p - Demonstration and student hands-on (machines and dust collector on)
Break for 15 minutes to allow water, bathrooms, and the one off cuts that people want to do. Any one on one that needs to happen can be done here.
12:15p-12:45p - Safety/Basics (Back to quiet time)
Instructor 1 - Band Saw/Sanders
Instructor 2 - Wood/Miter Saw
12:46p-1:15p - Demonstration and student hands-on
The pros to this, allows more students to be taught during a single training session. I think this is too optimistic, but if we had 4 instructors, we could possibly have 20 people get through woodshop basics in 3 hours.