To troll originally meant to "carefully and systematically search an area for something." Perhaps a bit of an archaic definition nowadays, but older or more literary people would probably understand it's intent in this context.
I wasn't thinking of trawl, in my mind trawling is a method of fishing, such as "Trawling for shrimp". Interestingly, the second definition on that page references "Troll". Following that link, it says down the page "SEARCH, LOOK; trolling for sponsors" and "to search in or at;
trolls flea markets for bargains". Perhaps both would work in the above context, however I would prefer trolling over trawling.