Perhaps you mean efficient rather than effective? It does seem to be quite effective, despite the superficially amusing fact that a very tall tower is being used to form a very small product.

Though whether it's inefficient in any other sense is, I think, open to question: The up front expense and difficulty of the tower is a one-time cost, and I'd think maintenance on it would be fairly minimal. I'd think other methods discussed in these comments would almost certainly incur significantly more overhead, particularly over the life of the facility.