I would stay sceptical, way to many things can go wrong and british plumbing is an art of it self.

I think this the sewer is more suitable approach. One company in Czech republic manage to pull it off after more then decade of research.

Article in czech, but there is a lot of pictures to get the idea.

https://www.lupa.cz/galerie/pilotni-projekt-unikatni-instala...