How can I link Products in a Deal Subform to the Products Module

How can I link Products in a Deal Subform to the Products Module

Hello,
I have a pricing subform on our Deals page and use a lookup field to associate a product with each line.

I want to be able to look at a product page within the Products module and see a list of the deals connected to that product. I have this working well with other lookup fields and custom modules but the products only get listed if you assign them using the Products Related list on the Deals page. But this is no good for me. 

Do I need to create a workflow which calls a function to assign products to the Products related list automatically when the subform row is saved?

Should I create some sort of new linking module (not sure how to go about doing that)?

Or is there a different / better way of achieving what I need?