Yes I am beginning to understand this to be true.
I think I got the wrong impression from information I read some time ago that showed topical 5AR inhibitors to be ineffective. However there does seem to be a good deal of information suggesting that inhibiting the local conversion of DHT can also be effective.
I have also read recently that dutasteride and finasteride can also act as mild-moderate androgen receptor antagonists, which could also explain some of the benefits when used topically.
I think I will be sourcing some finasteride powder to add to my daily topical to further cut down scalp dht levels.