I'm not sure what your asking for can be done with two lasers. Even if you could cause destructive interference at exactly a single point in free space, the original beam would still propagate after that point.
I love Lasers… there great fun but I’m not sure if you will be able to stop one in its tracks like that, you can get them to interfere with each other for cool effects but not terminate the beam, plus the alignment would have to be exceptional even to get them to hit the same spot in 3 dimensional space
Not only would you need to get them to line up exactly in 3D but you would need there phase to be exactly 180 degrees out of phase at that exact spot and every place after that as well, that if my understanding of the situation is correct. Either way this would be nearly impossible to pull of when taking into account alignment, laser dispersion and that you want it to be invisible from that point onwards...
