I have some sticks at home and they work like brazing only on aluminum. Never had a need for them but I did weld a couple of Coke cans together.
Worth having a couple around just in case. I did mine with a MAP torch, but the cans are thin and heat real quick.
I wouldn't expect porosity to affect results because temps for brazing won't be melting the metal and causing it to flow. Rather, just heating it up enough to bond the brazing material. Once you get a porous material to heat up and melt, then you have problems with expanding air pockets, collapsing empty spaces, etc.