i know vitamins are more regulated in europe than here, but vitamin c is something that can be taken in massive quantities - like 20 to 50 GRAMS per day. the idea is to acheive what is called stomach tolerence. you take so much that your stomach starts to ache. stop taking it until the stomach settles and then take more till it starts to ache again. this is similar but not as effective as as intraveinous. it is also safer, as any breach of the blood is not good.
also, i would nebulize the silver for maximum effect and use the oral route for the vit c and Sea Salt and distilled water.
steve is right about the die-off effect. i wiped out a yeast bloom with silver and it really made me tired from all the gunk it released into my system. it took me months to get it all. making CS at home is soooo cost effective. make sure to only use distilled water of the purest available and pure silver, not sterling or jewelry or similar.