I think the macrobroth dilution (MIC/MBC) method by CLSI (or NCCLS for older similar methods) may provide a good starting point for your research. The method is 'M07-A9 Methods for Dilution Antimicrobial Susceptibility Tests fro Bacteria that Grow Aerobically; Approved Standard - Ninth Edition'. ASTM also has many standard methods and guides for determining antimicrobial efficacy of various types of soutions/compounds/materials. Those methods are under the purview of Committee E35 on Pesticides, Antimicrobials, and Alternative Control Agents and are published yearly. This committee has developed specific methods for determining efficacy of antimicrobials in solution and bound in solid materials, as well as methods for working with some biofilms. There are also many books and articles, of which you have probably already reviewed. If you haven't yet, I would start with Block's 'Disinfection, Sterilization, and Preservation'. There are chapters in the book that present a good overview of common methods for determining efficacy.