I use a piece of clear air hose for an aquarium.Mine I got from my Aunt who does in home kidney dialysis.Same hose for a different reason.
If you have a second hand store around you,like St.Vincent dePaul or Salvation Army,check them out .Our local second hand stores always have used fish tank air hose.It is cheap even if you buy it new at the hardware or big box store.Cut it long enough so the hammer don't hit the nipple and a foot of it will last for a long time.