Concrobium sells mold control spray and the fogger. Which one has more lasting effect on the mold? Does the $135 cost of fogger justify the effect it has on the mold?
Properly applied spray is demonstrably more effective than fogging.
That being said, neither are good for use on the substrates where mold is often worst: wood and drywall.
In any case, the most effective means of addressing mold is physical removal and cleaning.