I've got a couple of them. I've had good luck with a cotton ball soaked with fish oil placed behind the trigger. I haven't tried rubber coating the trigger as mac mentioned, but I think that is a great idea.
I use a lot of the coon cuffs, too. Just like the "push" triggers on them vs. pull triggers. I put the coon cuffs in end of a 4" PVC pipe section about 2' long and shove one end of it down in the creek bottom with trap end facing the bank/coon trail. I dye mine black to really stand out. Work well in a pocket set too with bait in back of pocket and trap blocking hole.
The little griz traps are nice and small, and I can wire one up just about anywhere such as under root systems on banks, to a smaller diameter pvc pipe section, to a rebar stake, etc. etc.
I use them a lot around barns and have had good success with them there. I've taken a lot of possums with this trap, too.