To give you an idea of just how much money is being spent on paid search, take a look at Google. Google's AdWords program is the most used pay-per-click (PPC) advertising program available today. While the tech giant owns YouTube and Android, among hundreds of other profitable brands, AdWords accounts for roughly 70% of their revenue -- which speaks wonders for its effectiveness.
Essentially, what distinguishes direct from organic traffic today is tracking. According to Business2Community, direct traffic is composed of website visits which have “no referring source or tracking information.” A referring source can be a search engine, or it can be a link from another website. Direct traffic can include visits that result from typing the URL directly into a browser, as the simple definition suggests.
Like I said at the beginning, building organic traffic is hard. Anything that promises a shortcut to an avalanche of traffic will more than likely lead to a penalty down the road. Embrace the daily grind of creating great content that helps users and provides a solution to what they’re looking for. In the end that will drive more organic traffic than any shortcut ever will.
Regarding Link Detox, links it diagnoses as Toxic are generally fine as they're either not indexed by Google or have malware/viruses/etc., but I recommend a manual review of any diagnosed as Suspicious. I used it recently to get started cleaning up our backlinks and some legit sites and blogs were under Suspicious simply because they didn't have many links pointing to them.