Sorry I did not reply to your post previously but it slipped my mind. Basically I forgot.
Yes they do, they can make a big difference. A multifaceted approach is needed for best effect using QSI, EPI, enzymes and antimicrobials. There can be a considerable amount of microorganisms, they outnumber you by a very large margin and they do not get tired. There will always be a very large number which are at work following those chemical messenges. Stopping their commincation helps considerably, therefore their chemical messages are a key part to beating them. Quorum Sensing encompasses many different processes that microorganisms carry out by signalling. A specific number of organisms inside a biofilm will cause them to release one chemical message to leave the biofilm and spread to other areas. Another will make them strengthen the biofilm. Quorum sensing controls virulence and probably other lesser things which I am not aware ATM. Therefore you should begin to understand that blocking this communication can prevent them from doing unwanted things.
Even with this they can take some beating. Persister cells if not destroyed can rebuild the colony and biofilm. Those can be very difficult to destroy. My most successful attempt so far against the CFS microorganisms produced a strong discomfort which was fairly close in intensity to the one where I did destroy a large portion of another biofilm. I use that as a guide. That one did heal but not yet back to how it would of been before the infection. Unfortunately I could not of destroyed the persister cells so their biofilm colony was reformed.