I'm using beetle barns with a small piece of CheckMite+ inside. I place the barns on top of the frames and on opposite sides of the brood box. They seem to be doing a decent job. I don't think I have a huge problem with the SHB but generally end up with around twenty to thirty total in the barns after a couple weeks. Most are dead when I open it up, sometimes not. Longer than a couple weeks and bees will have sealed up the entrance holes.