Best thing to do when entering a training party is to have someone explain it phase by phase (Party leader or a friend).

Explain phase 1 then try to pass it. Move to phase 2 and so on til you down it.
This way, you make sure that everyone in the party is on the same page, and that there is no one who is lucky enough to dodged everything without a clue.

If the party is showing progress, the chance of rage quitting will be very low. People will stick around until the last phase or stay for a kill.