If you plan on doing the KJ once, it might be worth the $125. If you plan on doing this more often, and have a fleet of cars in your family, a bit of ingenuity can go a long way.
I have a friend that modified an A/C fill fitting (you know, the Autozone type where you can buy cans of refrigerant and refill your A/C yourself) to fit the cans of fuel injector cleaner that shops use. He somehow weasled Pep Boys to sell him some from their service department. I was unsuccessful a few years back when I tried to get them to do it. Maybe you can find somewhere to purchase it online?
Basically, you connect the A/C fitting to the can of cleaner, and you hook the cleaner/fitting to the fuel rail. You pull the fuel pump fuse/relay and open the valve for the cleaner. As it’s an aerosol and under pressure, it’ll pressurize the fuel rail. You then crank the engine and it’ll fire up. The engine will run just on the cleaner while it cleans your injectors. When it runs out, you disconnect it and reinstall the fuel pump fuse/relay.
I used something similar on my ’91 Daytona when I was in High School. Our Autoshop teacher had a similar setup that the school purchased, except instead of an aerosol can it used an aluminum receptacle with a screw lid. You hooked an air compressor to it for pressure. I was the guinea pig, so I got to use it for free. He’d charge $4 (cost of the cleaner) to any of the students who wanted to use it. I had no issues, didn’t foul sensors or cause problems.
I’ll probably do this on the KJ and my wife’s G6 when the time comes. Both are <50k miles, so no need for now. IMO, Seafoam is good, but it’s still very diluted.