I have not used the upper cylinder lube product itself except in the form as a carb/injector cleaner which I believe is also claimed by Lucas to be an upper cylinder lube. I have used the injector cleaner on both my 93 Nissan and the 04 Tundra v8 and have had good luck so far.
When things get really dirty, I use Seafoam which I have found to be an excellent product when used as directed. The Lucas stuff seems to work really well as a maintenance cleaner to keep the injectors and valves clean. I found a small gas station off the Interstate in Missouri that sells it by the gallon for 20 bucks - not bad when you have to pay 6 or 7 dollars at the parts store for the quart size. Then just keep the old empty quart sqeeze bottle and use the gallon as a refiller. I use every 2nd or 3rd tank to keep the fuel system going good.
I kind of doubt you would need an additional upper cylinder lube on most modern engines with a good crank oil/synthetic. The small amount of blowby past the rings keeps the pistons sliding well and anything combustible on the top side would either carbon up or go out the exhaust ports with the spent fuel. Any experts out there feel free to educate me on the benefits of upper cylinder lubrication if I have this wrong....