UV sterilizers work by one metric and one metric alone, contact time. Whether the thing is twisted, straight, curved, S-shape, whatever is irrelevant. Too much contact time and you kill everything including the good stuff and too little contact time and you don't kill anything.
This is why UV sterilizers need to be on a manifold where you control the flow independently from the main return. If you want a UV unit there is only 1 brand to look at, Aqua UV. They are the industry standard and not overpriced aquarium branded crap.