It might be able to arrest an infection's internal spread to other tissues and cells, but the virus would still live in existing infected cells. They'd have to find the therapeutic levels necessary to "cleanse the blood", and do clinical trials to look for side-effects (since they'll've introduced a solution of foreign bodies into the bloodstream). It might be that the levels to cleanse the blood are too high in most cases to be economically or therapeutically viable; or maybe not.

In any case, the approach is pretty neat.