If cold/flu something in the sinus/lungs using CS( Colloidal Silver ) to get to the lungs and sinus directly gets more silver where it needs to be to knock out cold/flu. If taken by mouth it has to go through the whole body and that takes time and more CS! Putting the CS right at the site of infection/virus/bacteria puts a higher level of CS right where it is needed. Drinking it will take more and longer to effect.