I have had two sinus surgeries, the last one was in late March.  I had
Augmentin after the surgery.  In June I developed a nasty sinus
infection and was on Augmentin again which SEEMED to get rid of it.
However, within about 10 days of finishing the Augmentin I felt it
start to return and it came back just as bad as before.  I tried to get
rid of it by irrigating with hypertonic saline 2-3 X daily (I have a
Hydropulse) but to no avail.

Here are some interesting facts:

1) I have never had a sinus infection which required antibiotics prior
to my March surgery.  The June infection is the first time I've had one
requiring antibiotics.  This infection has caused fever and an
unbelievable amount of dense crud is sometimes flushed out with the
hydropulse (and hard blowing which I know is a no-no, but it came
out....)

2) I assume that my current infection is the same infection which I
thought was taken care of in June by the Augmentin.  I assume this is a
recurrence of the same infection and that the Augmentin did not totally
eradicate it.  This time, I am on Ketek for 10 days.

3) The June sinus infection began during a 4 day period when I was
moving and I had packed away my Hydropulse, assuming that a few days
without irrigating would not be a big deal.  It is very interesting
that it happened during this period and that resuming irrigation did
not prevent it from becoming completely unmaneable without antibiotics.

4) This current infection seems to have started after once again not
irrigating for only TWO days... I was gone for a weekend, didn't bring
it, and when I got back I could feel a sinus infection starting.  Once
again, I tried using the Hydropulse to nip it in the bud to no avail.
It got really bad (fever 101.3) and just got worse every day until
today I went in for more antibiotics.

5) I moved out of state sooner than expected so I can't see my surgeon.
I plan to make an appointment with a new ENT to check me out.  (I had
to move prior to my final post-op appointment so I probably need to
have my sinuses looked at anyway.)

I want to get rid of this thing and KEEP it gone this time.

Am I correct in assuming that something must be wrong for me to develop
a sinus infection after failing to irrigate for only 4 days and 2 days
respectively? Perhaps I HAD the infection the entire time but it wasn't
able to take hold until I quit irrigating for those brief periods?

What I would like to know is, what can I put in the saline solution to
kill bacteria and prevent recurrence.  The only thing I have read is
Xylitol which I ordered a large supply of, and hydrogen peroxide which
no one can say with any degree of certainty whether it's safe or not,
even at very low levels.  I've seen people report up to 3 tablespoons
of Xylitol in the Hydropulse basin.