Check out the video of this petri dish experiment by Angie who is a RN (pardon the commercial at the start) which included a test of the Smart Colloidal Silver I manufacture and sell. My comment to her about the video is as follows:
The Smart Colloidal Silver performed exactly as I would expect it too. Unlike essential oils, it is not an aromatic. So, it will only kill microbes it can come in direct contact with, which is the dampened disk and possibly the area of the dish immediately adjacent where the fluid migrated out to after the wet disk was placed in the dish. The migration away from the disk into the dish would diminish with the distance from the disk and not be as complete, allowing some encroachment of the microbes into that outer zone around the disk after a longer time.
We use Young Living Essential oils, the Smart Colloidal Silver we manufacture, plus other high silver concentration products we manufacture and sell, all of which can be found at the link Angie provided. The result for the oil that did best is simply fantastic which you have to see to believe.
Outstanding experiment and video Angie.