IT simply doesn't work. As i know Merck had trials also with topical finasteride before releasing in, and the results sucked.
Imagine, if topical finasteride would work, why would they made a pill, which has sides?
There are tales on the net that, supposedly, topical finasteride is better than oral one, and it even reduces more DHT, but i think they are lies and only marketing strategies for some people to sell their overpriced "finasteride solution" .