Tim:
If I were to trap otter on dry land, I would use the plain old dirt hole set. I've caught dozens of otter over the years in hole sets made for coyote along waterways. If fact, otter were so nuts over one experimental coyote lure that it became Lenon's Otter Super All Call. Would catch the same otters over and over with the same lure. Dirt hole sets and their variations will harvest just about any animal. The hole always represents food and curiosity and when an alluring scent is added, BINGO!
Ace