Never tried alumaseal, but I was on a road trip once with the family, and the radiator on our Suburban started to leak. Being that I was about 1000 miles from my house and tools, I stopped into a service station and bought some off brand radiator stop leak. Well, 6 months later I was replacing radiator, water pump, and hoses. That crap got everywhere and started plugging things up.
Just a traveling cat in a tall black hat riding a goat. Nothing to see here.