From the article I gather Birkenstock makes EVA sandals now? I wonder if that’s a factor. Mine are the “traditional” style, leather straps and footbed. I’ve never had a problem with mine, nor a complaint from my wife, who is more than happy to tell me when my running shoes stink.

In summary, I guess I’m not the person to ask.

Just scrub the footbed with water and marseille soap. It always worked for me with the traditional ones made of leather. A lighter method is to scrub some bicarbonate of soda gently for a couple of minutes, leave for a day and then clean up.