False, and I'll chime in here.
Before finasteride, semen was not watery at all. I started on finasteride, and it became watery...but only if I did a "quick jerk". When I have sex, it's normal.
3 months ago I got a batch of finasteride from overseas that was a different brand, but I took it anyway. My head started to itch again within 3 weeks of taking it. During the 2 months that I took it I noticed that my semen went back to "normal" 100% of the time. I got a script for generic Proscar last month and have been taking legit finasteride again....and it's back to more watery when I do a quick jerk.
So, ya...it can go back.