I don't know if a bit of  'commercial' Echinacea tea would be 'enough' to provide any noticeable improvement for a deep-seated bacterial infection, but I did find last night that Echinacea IS very beneficial for all types of gum/dental issues (just another benefit that I hadn't know previously).  Of course I knew that it's 'huge' for fighting infections, but not that it had been successfully used for gingivitis, pyorrhea and many other similar issues.    I'm still hunting down more 'technical info', but out of what I've found so far, here's a great overview:

From here: http://medherb.com/Materia_Medica/Echinacea_as_a_dental_remedy_.htm

Echinacea as a dental remedy

by Paul Bergner

Medical Herbalism 12-31-93 5(4): 9

Many Native American tribes, including the Omaha Ponca, Oglala Dakota, Cheyenne, Crow and Commanche used echinacea as a dental remedy. Reported uses include:

- The fresh root chewed for toothaches

- The root juice used on “hollow teeth”

- The whole plant infusion, or the chewed root, for sore gums.

Fresh root or the fresh root juice have a high content of mucilaginous polysaccharides, with both immune-stimulating and wound-healing properties. The isobutylamides in some echinacea species (responsible for the “tingle” of echinacea) also act as a local anesthetic.

Although “hollow teeth” are not so common today as they were a hundred years ago, bleeding gums and periodontal disease are still quite common, and echinacea may be useful in preventing surgical treatment.
  Copyright 2001 Paul Bergner

I'd suggest "swishing" with the tea for a few minutes several times a day.  Put the loose herb in a kettle/pan, bring to a boil, cover, and then simmer for at least 1/2 hour.  Then (for the best, most strongest benefit), take of the lid and continue 'simmering off' the water until there's about 1/2 of what you started with...then swish with that.  (and be sure to keep us updated!)

Thanks for uncovering yet ANOTHER specific/fantastic benefit of Echinacea!

Uny