I am definitely not an expert by any means, but the word "dilution" istelf means "the process of making weaker or less concentrated".

So, no, it doesn't rid your body of anything. It simply "dilutes" the sample so that the concentration of THC is below the cutoff. That's also why the dilution is not permanent. It only lasts for a few hours. If it completely eliminated the THC in your body, it would be called "detoxifying". Unfortunately, only time can rid your body of THC.