Yes, i've used it in 2 vanagons with the drip (the moral equivalent of 
the clap) with moderate success...  seems to stop the warmer weather 
drip but when it gets below 0 F, i still have a drip until the engine 
warms a bit.

BUT Aluma-Seal has some other interesting properties!  it is
essentially just powdered aluminum, when mixed with 12N nitric acid
it causes a highly exothermic reaction!  WARNING: don't try it at
home or anywhere else (yeah, right).  i found this out the hard way
when making up a set of metals standards for some AA (atomic
absorption, not the booze thing) spectroscopy work.  the sight of
that  violently shaking, boiling, spewing volumetric flask scared me
more than any other Stupid Thing i've done in labs.

also, powdered Al is what creates the white 'flash' in fire-crackers.

-dan