Finding real primo tabs is not easy for one. Secondly, they are not very effective at 25mg a tab you need 6-8 tabs daily.
Dbol and primo tabs togehter will yield gains, however, how maintainable will they be? Dbol main gains come from the water retention it creates, which is commonly lost once the product is ceased so taking it alone is not ideal. So adding primo would help but how effective it will be is really diffcult to say.