I see little risk--but I wouldn't expect miracles.  Listerine is a
mediocre antimicrobial.  I'd concentrate more on the interdental brush
and less on what you put on it.
    If you wanted a trial with a more effective antiseptic rinse, I'd ask
my dentist if a prescription for Peridex (chlorhexidene gluconate 0.12%)
is a good idea.  It can cause staining and occasionally  change in taste
sensation though, so generally I don't have my patients on it for more
than a couple of months.

Steve

My periodontist suggested root planing for two pockets, one of 4mm and
the other of 6mm.

I asked whether if the use of a mouthwash might obviate the need for
perio intervention. He said to try Listerine.  We agreed that for the
next 3 months I would try to keep the area clean and see if I could
"cure" the pockets on my own.

I am now trying Listering and am dipping the small interdental brush
into Listerine to get it between the teeth.  Not using it as a
mouthwash but applying directly between the teeth.

Question:  Is using listerine in this way, directly between the teeth,
a good idea.  Or might it damage the gums in some way.  Should I stick
with the mouthwash....or should I do both.

Thanks for any advice.