if you really want to be hard core about cleaning your injectors you can buy a rebuild kit off ebay that has new caps, rings, and filter baskets for around 25 dollars. soak the injectors in gasoline overnight. get a spare injector connector from the jy. hook one wire to a 12v source and another to a ground and watch the dirty stuff come out. replace the supplied parts and voila. damn near new injectors.
Can you be more specific about the brand of cleaner you are using ? I know there is one kind that connects to the fuel rail at the shrader valve (passenger's side in back of the alternator), but from what I've read it is a pretty involved process, meaning you are supposed to disable the fuel pump and maybe do some other things. What do the instructions say to do ?
with thoes style injector cleaners all that you do is attatch it to the schrader on the passenger side, disable your fuel pump, hook up the can open the valve on the can then start the car and let it run until it dies.