Firstly, how do you know that the person replying does actually have health knowledge? The internet is full of people who think or claim to have knowledge in areas they actually know nothing about.. not trying to sound mean, just don't think it's sensible to ask for health opinions of this nature on a drugs website full of randoms
Secondly, ketamine affects your bladder causing inflammation and scarring, not your kidneys. "Cleansing" your kidneys (or even your bladder) in any way would not stop the ketamine (or more specifically it's metabolite norketamine) from doing the damage I suspect..
But, as you asked, I personally think they both look like complete and utter rubbish and would not believe their claims for a second.
Things like this make me so angry - I've seen the damage long term ketamine use can do to the bladder, and unscientific and unproven claims like this could do a lot of harm as they could prevent someone from seeking medical help or lead someone to believe they are protected when they are not..
This is just my opinion of course. I am sure there are lots of people who would disagree with me. I, however, like my medicines to be based on actual science and have a good evidence base..
(Hehe sorry if I sounded grumpy, just a pet hate of mine. Your best bet is to be moderate with your ketamine use and stop at the first sign of any urinary problems, and see a doctor.. good luck

)