Cocoa mulch can develop a white, musty-smelling mold on its surface when used in shady areas or after a period of wet weather. You should be aware that cocoa mulch can also become extremely slippery when wet, so it might not be good choice for a walking path. Cocoa mulch breaks down relatively quickly, and the mold is just part of that process. Stirring the mulch or raking it seems to be the best method of breaking up the clumps, drying it out, and improving the appearance. Applying it too thickly will encourage mold development. It would be wise to avoid inhaling the mold when working with it. The mold problem should get better over time. Cocoa shells are quite attractive (at least at first), have some value as a fertilizer, and do resist wind. However, their high potash (potassium) content may harm some plants, so they should never be applied to a depth greater than 2 inches. You should also be aware that dogs can become seriously ill if they ingest cocoa mulch. You might want to simply add some wild rice hulls, wood chips, or shredded bark to the cocoa mulch to improve the appearance and make it less slippery for walking.