It is indeed difficult, But there is still a way and it may need your sacrifice, especially with your career. I've noticed that children being raised in the countryside or a province area tend to be more polite and have better manners rather than those who lived in the city where they are easily exposed to bad experiences.
Also, constant guidance is needed. Even if they haven't experienced it you should explain it to them before they learn it from other people. Lastly, it is important to give them support but never limit them to exploring things. Them, knowing that they always have your back is a good thing.