I think you are confusing tank 'maintenance' - (regularly cleaning the tank by either mechanical or chemical means) to prevent/remove the deposition of fungal, etc. debris/'crud' - ... with 'polishing' which constantly removes at a fast rate the 'nucleation sites' from the fuel which if not removed then 'grow' (agglomerate) into ever larger and larger particles. Recirculation Polishing isnt a substitute for proper tank 'maintenance' (cleaning, etc.), as polishing is a methodology that extends the interval between 'cleaning' AND reduces the particle load to the in-line filters. Recirculation polishing a dirty or crudded-up tankage is wholly 'worthless' other than in an 'emergency'.
In 'filter-speak' if you have to remove more than 0.05% (wt.) of 'debris' from a fluid, you're not 'polishing', you're 'reclaiming'.
Neither of the methods that you cite are effective for 'recirculation polishing' as neither will result in the 'clarity' and particulate levels of fuel that is needed for a modern diesel engine ... without excessive expense or extremely low over-all removal efficiency.