Agreed.

There are many legal reasons that they could not perform a body search for anal cheating devices, butt more importantly: human perseverance has shown that some communication devices will always be able to stay hidden...no matter how invasive the search.

You could fix the communication by putting participants in something like a Faraday cage, or lining the walls with lead etc.

However, if someone puts the actual chess computer inside their body, even those measures won't help.