What makes you think ionic silver would damage the biofilm in the first place? Biofilm is neither bacteria nor virus. And CS (or IS) is no more caustic than water (which it's 99.99995 percent of).
I would have to see serious data to believe that CS would harm biofilm given it's one of the most benign substances you can ingest.
You SHOULD be careful with DMSO OTOH since whatever comes in contact with it (when used externally) has immediate access to the blood stream. Even scarier to think how that might work when taken internally.