fuel additives?

I have never been a believer in Liquid rings or other Mechanic in a bottle gimmicks but I am a true believer in seafoam. I now use seafoam every other tank and in the winter I use it in every tank for condensation and crap gas because I dont run my boats that much in january and february . I think it makes my old 2 strokes run smoother .A friend of mine who works on outboards says that Techron and Ringfree et all is probably just as good and that if you buy chevron gas it already has techron in it..Frank