YouTube has a few videos showing players using explosive traps. Like
this one.
Trap skill, including explosive traps, is a love-it or hate-it skill.
Traps are best suited in two general situations.
First, using them in narrow places where you will get the enemies to come to you as you attack with range. For example, placing a trap by a door, than getting the enemies inside to run out to you. The damage and slow down will help you bombard them with your trusty bow.
Second, kiting in a circle while dropping traps. This can be slow, but can keep you out of harm's way while other skills cool down. The traps do damage, and the slow down can be helpful in keeping your distance.
There's a lot of possible uses for the trap skill so the above two aren't a complete lists.