In general it doesn't hurt, but if using Top Tier every tank, you don't need to use additional cleaner very often. A bottle of
Red Line SI-1, or can of
BG 44K, won't hurt every year or two... but really is not needed every few months. If you do use a full bottle/can, try to do this on the tank just prior to an oil change, as the strong solvents can contaminate the oil a bit. If you want to use something more often, use a couple ounces of Red Line SI-1 per tank.
I did a lot of research on this years ago and my personal regimen is to use a full bottle right after purchasing a vehicle, as I have no idea what the previous owner(s) have used for fuel or additives. But afterwards, I don't add anything on a regular basis if the engine is running normally. Maybe a bottle of the good stuff every 5 years or so if I remember.
For a really good tech discussion on this, read the first Amazon review for SI-1 by "Slipstreampilot"
at this link. This also explains why some additives are more expensive than others, due to the PEA levels. There was a different SI-1 review where someone had monitored MPG data over the long term and found a noticeable, repeatable improvement with the ounce or two per tank... can't find that review at the moment though.