For 15 years we have cleaned the fuel system, by using contact cleaner, blow-out, from the fuel tank all the way thru the nozzles, Then put oil in the pump, and put the pump and the nozzles in plastic bags until the the next race. We have never had any problems with any part of the fuel system. But I have seen pluged nozzles with guys that don't clean their system. I've heard some racers clean with gasoline and then run the motor before they put it to sleep.
VP makes a few different Alky formulas, M-1 is pure alky and does pass NHRA fuel check.
M-3 has top oil added for sprint racers because they run their motors longer and are looking for valve stem lube, but it will not pass fuel check, as does putting WD-40 in your pump, we have failed fuel check when we used WD-40. I use Marvel Mystery oil.
M-5 is alky with some nitrate added [ nitro family] I don't know who uses M-5, maybe RC planes, but of course it will fail NHRA fuel checks.
Now if your tracks don't check fuel, and you are looking for more HP, just add 10-20% nitro, but clean your fuel system !
Jon