The first time I had very bad sinus infections I was working in a live in situation and had nothing with which to help myself, very bad situation. I thought I was going to die.
Second time, years later, it was connected with an upper molar that decided it was time to torment me. So it was a complex thing, I took Zithromax, which is about the only antibiotic I can take.
Now if I feel that something is lurking, I do extra neti, and also neti (I guess that is like a sinus flush) can be done with diluted herb tea along with the salt. Basil, oregano and thyme teas are all strongly antibiotic, tea has to be very well strained and diluted.
Was the colloidal silver diluted or at the usual 10ppm? Ours pretty much is 10ppm. I use it to rinse with after teeth brushing/flossing.
A sinus flush is mixing 2 T Colloidal silver w/ 1/8 t Xylitol (the Xylitol adjusts the ph to stop burning sensation) and I heat it 9 sec in microwave using a short coffee cup, using a dropper, lay on your back with your head down towards the floor, fill each sinus with mixture, stay in this position for 3 minutes, have plenty of paper towels and sit upright and blow your nose. This will bring out all congestion. The colloidal is 10 ppm.