Mattster, you can place cigars in direct contact with the bag -- if there is no standing water on the bag or the beads beneath the mesh. For most users, that means you'll need to dry off the surface with a towel, and perhaps wait a bit for the beads to absorb any water on their surfaces. You might also cover them with a dry piece torn from a towel, or a sheet of Spanish cedar (a layer-divider from a box of cigars), and then put the cigars on top of that. But the best solution might be to use a wooden humidor divider to keep the bag separate from the cigars themselves.
I recently converted my desktop humidors from those propylene glycol gels that come in glass jars. Since I had several of the jars, I cleaned a few of them out thoroughly, poured the beads to about one-inch depth (maybe a little less), then replaced the perforated covers on the jars. The mesh bags or Heartfelt's perforated plastic tubes provide more surface area (good for helping a humidor recover quickly after it's been opened to grab a tasty stick), but I already had the jars and decided to "recycle". I'm thinking about buying more beads and making a coolerdor; I'll probably get a couple of bags to hold the beads for the cooler, and possibly add more beads to my desktops; extra beads will help the desktop humidors compensate for the extremely dry indoor air during winter, and I still have gel-jars that need to find gainful employment.