You are right, that's one of the best way to handle such situation and another is to keep a close eye on them, monitor their devices because like you said, some kids can secretly be using their device to gamble online without the attention of the parents. Another thing is to keep a very friendly and open door relationship with your kids so that, if they actually go online and see some of these misleading gambling advert and videos, they would have to ask you (their parents) what it's all about.
Yeah, this way one as a parent can easily keep a close eye on their kids and giving them proper directives and guidance without acting or sounding hostile towards them, which is very important in maintaining good relationship with children. Ye children at times, can be really rebellious but that’s when they’ve lost confidence in you as their parents and they can no longer rely on you for guidance.