Second
Grains are few. Imagine the last few grains trickling down the hourglass. You only have a second left.
Normally an hourglass has sand to count the seconds, but yours uses grains. Imagine just a few grains left, and watch them trickle down as you count a second, and then another second.
びょう
None
None
After the final seconds go by, your awful B.O. (びょう) appears.
Your hourglass timer was a timer to specifically let you know when your B.O. was set to return.