There are two versions of Techron - one is a "lighter" cleaner that can be used every 3K miles or so, the other is a "heavier" cleaner that should not be used that often.
The "heavier" cleaner is very effective and will clean out the injectors and fuel system. Use it when you notice engine roughness or missing.
As a practical matter, all fuels have cleaners in them and these products are essentially unnecessary in this day and age. If you buy Chevron gas, it alread has the techron in it.
Bro, you sure about that? I know you have noticed the ethanol they put in the fuel these days and I must say they can raise H E L L, especially if you leave it there unused for a fair amount of time. Normally that can be rectified by using stabilizer.