Question
The problem is I need to do this at scale, quickly, in a whitehat way. I thought about pinging, hiring guys on Fiverr to submit to social networks or using Scrapebox's rapid indexer add-on - but I think that all of these solutions are going to look mighty suspicious to Google and result in penalties.
Answer
I would recommended:-
1.Make clear product hierarchy.
2.Proper product categorization.
3.Create separate sitemaps for products, categories and blog.
4.Use interlinking.
5.Use rel next and rel previous on product pages.
6.Use rel canonical on pages with session ids to control crawl budget.
7.Try to include more products on main categories instead of dividing them to multiple pages.
8.Use breadcrums.