He has been on Dbol for 4 weeks already.
Dropping the Dbol & doing 25-50mg of winny per day is definitely Gtg.
I wouldn't recommend running any toxic Orals for more than 6-8 weeks.
You could run Anavar for longer maybe but it's not commonly recommended to do so.
No amount of winny or any other steroid will bring any amount of vascularity if you aren't already lean enough to be able to see your veins in the first place though.