Just my 0.02
Are you contracted to teach it, or are you an employee of the company?
In my case, I was hired by the company and am a full timer.
I just familiarized with ISO (many thanks to the cove) and spent a lot of time on the assembly floor, learning what was going on. Believe me, when I first started, I thought I was going to be lynched, as they thought I was going to tell them how to do their jobs.
I spend a lot of time on the assembly floor to this day talking to the production staff.
But I digress.
In my experience, if you can, don't lecture or make up a reason to joke with the employees. Let the joke come naturally if the circumstance happens.
Let the employee tell you about their job in casual conversation on the assembly floor.
Soon, you will find they aren't trying to lynch you, but will even come to you for advice.
The rest will fall into place.