Do viruses float freely in the air, or are they mostly in aerosolized bodily fluids when from an infected persons coughs and sneezes? Cloth masks are great at trapping those and greatly reducing the "muzzle velocity" of droplets that do escape.
Test 1, spray from 2 feet. Of course the paper was soaked.
Test 2, a cloth mask placed on the paper. It gets damp, especially if left in place.
Test 3, a cloth mask over the spray bottle. The mask blocks almost all of the spray.
We did not bother with test 4 (2 masks) after the 3rd, but I think they understood the point.
We did retry 3 with a medical mask, with 0 spray through.