I don't have an answer that is based on data, but I'll do my best to provide a recommendation, or at least the things to consider in your decision.  

With EFB, we are trying to control the spread of a widespread bacteria, focusing mostly on ways that it could get back into the larval gut.  Things like boxes and woodenware, are lower risk, because there isn't always a clear pathway as to how it can get from a bottom board, for example, to a larval gut.  Foundation, however is a bit riskier, so we would be more cautious.  Plastic foundation is expensive to purchase, but it is labor intensive (in my opinion) to reuse.  You would want to clean it as best you can (Scraping/ power washing), and then you would likely soak in bleach water, and then re-coat with clean beeswax.  

At MSU we tend not to re-use plastic foundation, because we aren't set up with this process.  In my own operation, I only use wax foundation, so I can just melt it out and re-use the frames.