Air Filtration Math

I've got a 10" square box fan I was thinking of bringing with me to Texas, partly for white noise and partly because I was a little too warm in the hotel we stayed at last time. (I'll be in my own room this time, so that's less of an issue, but still.)

I can't find 10"x10" air filters, but I can find 10"x20".

If I fold the 20" filters in half and tape the dickens out of any tears, do you think I could use two of them to make a mini Coris-Rosenthal Cube for my hotel room?