Hi Sibel,
To the best of my knowledge, there are No documentation available in public forum on, how do we implement eCommerce tracking via DTM.
That being said, I did implement Adobe Analytics eCommerce solution (aka SiteCatalyst) via DTM and would be able to help you with your specific queries on the same forum.
Regarding your question on s.products variable, you might want to write a custom code to capture the product string values, use custom code section of an Event Based Rule or Page Load Rule depending on your requirement.
Do like the post should you find useful by clicking on the Heart Icon and move this to Solved status for the benefit of other users of the forum.
Hope this helps!
Regards,
Harsh Kabra | Adobe Certified Expert: Digital Analytics® & SiteCatalyst Implementation & Reporting®