According to social research, we generally don't like advice when it comes to entrenched problems and rarely yield to it.
In
Influencer: The Power to Change Anything, a book I would recommend to anyone interested in motivating others, the authors (Kerry Patterson, et al) explain that people will change difficult behavior only (1) if they think that the change is worth it; and (2) if they can actually do it. The next best thing to doing the task themselves is watching or hearing a story about another person, who is similar to them, doing the very same task.