I may elaborate, in the hope it is useful.

You should never submit any work to a conference or journal you do not know and follow beforehand.

To be more explicit: a good rule of thumb is that if you are not familiar with the publications of at least some of the committee or, if you were asked to suggest reviewers for you research out of the scientific committee members, you'd be hard pressed to name a few, you should not submit anything.

Your students should know that. If none explained something similar to the above, then you should have.

As you get older, I find I only follow 1-2 quality publications. I often get invited to dubious / shady conferences and I just hit the spam button. All of my peers do the same.