I consider myself to be a silver nanoparticle enthusiast and I make my own so I know what I am taking, but I have never had much luck fighting a cold by taking colloidal silver orally at any dose up to a quart per day of 20 ppm colloidal silver nanoparticles, even when I took a quart per day for a month straight. In the middle to second half of that one month run, I eneded up catching a cold and it pretty much played out as colds usually do for me despite being primed with silver nanoparticles well before I caught it. The silver nanoparticles taken orally just did not do much to fight the cold that I could tell.
More recently I have switched to using an ultrasonic humidifier for short durations several times per day inhaling directly near the output port. I chose the ultrasonic humidifier because it delivers a considerable amount of silver nanoparticles directly to the areas that are most affected by a cold in an amount that is effective and probably quite a bit more so than a nebulizer can deliver in the same amount of time. This is important because of the huge surface area of the lungs which is said to be 80~100 square meters or about the size of half a tennis court. A nebulizer will take a lot longer to deliver what the humidifier can deliver in minutes and because of that huge lung surface area, that is a very important point.
If I start at the first hint of a cold, the symptoms have gone within 24 hours or less. If I am unable to start right away, the cold is usually gone in about three days or less and symptoms are greatly reduced from what I have come to expect as my norm. Normally if I don't try to stop a cold, it drags on for weeks and often times settles into my chest in which case I have gotten a cough that lasted over a year and that has happened at least 4 times that I can remember. So as far as oral silver nanoparticles for a cold......not effective for me, but delivered via an ultrasonic humidifier......A+.
I only put a small amount of 40 ppm silver nanoparticles (about 4 ounces) in the humidifier and breathe the vapor in deeply as it comes from the output port of the humidifier for about 7 minutes three times during the day for a total of about 21 minutes per day. Usually symptoms are gone the first day, but I might continue for one day after the symptoms have gone. Throw away whatever is left in the humidifier when I am done.
In any case, it is the ultasonic humidifier that makes all the difference in the world for me when using silver nanoparticles to fight a cold. Just 4 ounces compared to quarts taken orally that had little to no impact on my cold.
When I was growing up and I would get a bad cold, she would cut up an onion and sprinkle a generous amount of sugar over the slices. I would take a tespoon several times a day and by the next day or two my cold would be gone. To this day doctors cannot cure the common cold and this still works. Beats all the new drugs they try to put on you that harm the liver, heart, kidneys and more in my humble opinion:)