Selection of a cleaning technology also depends on what, exactly, you are trying to clean out of the pipe. The stuff I've seen in Vent Recovery systems required drifts, chisels and hammers just to recover enough lumen to begin thinking about other methods.
In any cleaning operation, you also have to worry about the volume and nature of the contaminated cleaning media you produce, what you're going to do with it, and how big a mountain of paperwork you'll need to originate, disseminate, get approved, process, archive, and eventually destroy.
... and what you're going to do with all that destroyed paperwok, and how big a mountain of paperwork you'll need to....
Selecting between chemical or abrasive cleaning, as the only permissible choices, and choosing just one, sounds like an academic exercise, conducted by a teacher who's never actually had to unclog a pipe In Real Life.
Mike Halloran
Pembroke Pines, FL, USA