Any additives to the fuel will not clean the intake valves.
Besides the 3M kit which works nicely, BG44K has a good product, but to use it you must have an injection system. The nice thing with the 3m kit is that it comes with its own. I get the 3m kit at Autozone for $40usd plus a $10usd mail-in rebate. If you can rig up your own injection system, then your product options are greater. BTW, most of the really good(expensive) intake/fuel system cleaners are simply "mineral spirits". One gallon of mineral spirits cost me $15usd and an 8oz bottle of one cleaner costs $25usd and one can of BG44K costs $35usd. Also, I add 8oz of min. spirits to a full tank to clean my injectors every other oil change (10k miles).