I would have to understand the culture a little bit more to give you sound advice on a cultural issue.
My first recommendation on your approach would be: Don’t overwhelm them with jargon and tools. For example: if you want to brainstorm root causes, just ask, “So, what do you think is causing this problem to happen?” and start to write them down. Next, organize those possible root causes into a Fishbone later and share it.
If they’re not caught up in the tool instead of the activity, you’re are in a tough position, because fixing other people’s processes is not a winning strategy, and can create problems with sustainability later too.
I would work as much as you can to involve the people in the process as much as possible. If they ever feel like YOU are fixing their process rather than THEM, then you are going to run into trouble. Help them be the stars and make them shine!