Those products are basically maintenance items - they cannot remove the waxy products that build up on the injector and disrupt the spray pattern.
It is best to get the injectors cleaned external to the engine, because you can then have them checked for correct spray pattern. Cleaning them in-situ "hopes" that the job gets done properly.
If you look in the Yellow Pages (on-line or on paper), under Fuel Injection, there will be various businesses, including mobile services, listed. Find which one does flow testing and spray pattern testing.