The problem with using Fenbendazole or Flubendazole is that they tend to kill snails.If they worry you, you can get rid of them by trapping or using Panacur (Fenbendazole).
So removing Planaria from a tank with snails you would like to keep is nearly impossible afaik. And I really like snails.
Traps to me are just a band aid, I dont believe Planaria will ever be completely removed only with a trap.