I think this would be very difficult and you would become weak and unhealthy at the end, if you were able to stick with it.
According to the NHS literature, the NHS milk diet is a pre-op diet to be followed 2 to 4 weeks before surgery. It's not intended as a weight loss diet. It has a specific purpose and that's to shrink an enlarged liver to make bariatric surgery safer. If someone is recommending you follow this for 8 weeks, it's my opinion that they need to have their medical license reviewed.
From your post, I get the impression your gut instincts are telling you not to attempt this diet, and someone misguided is pushing you in that direction.
If you are interested in improving your liver as well as your overall health and kick starting your diet, I would strongly suggest a diet of lots of fresh vegetables, some fruits, limited proteins, and limited whole grains. Eliminate all added sugar, artificial ingredients, and processed foods. Increase fiber naturally with the right food choices. It's so much easier to stick with. You will feel a million times better in 2-3 weeks. Detoxing simply means to stop putting bad stuff in our bodies, and start putting good stuff in.
I wish you the best of luck on your journey. Weight loss can be frustrating at times, but it shouldn't be dangerous. Follow your instincts
If you are still looking for someone who is or has gone through this, I don't think you'll find that person on our forum. Maybe they can direct you to a FB group or something similar through their service.