I think that in those cases the clean diets and trainings did more for fat loss than Nolvadex. It is a SERM, so it will reduce the estrogen levels within the body - I don't see how it can effectively help burn fat. Only if it theoretically reduced the estrogen levels to such an extent, as to help burn fat, but this would definitely not be a healthy thing for a lady, as you need estrogen for proper functioning.
If you want something that will really make a difference in terms of fatloss, Cardarine GW or SR9009 would be a much better alternative. They will actually help you burn fat, and they will also increase your endurance and improve recovery, which will lead to even better fat loss. The best thing about them is that these compounds are non-hormonal, and they will not cause side effects. At least they do have a scientifically proven ability to promote fatloss, which is not the case with Nolvadex.