+1 to cheap vodka in airlocks and StarSan in blow off jugs. On brew day, I always have a bucket of StarSan for things like pump hoses, etc. I just fill the blow off jug from that bucket when putting things in the fermenchamber.
I use cheap vodka in my airlocks,but Starsan in blow off jugs. One scientist type member came on here a month or so ago & said cheap grocery store vodka doesn't have enough alcohol. So I thought about the grain alcohol liquor stores sell. According to him,that would do a better job.
Buuuutttt, the airlock is to exclude air, not microbes.