Physics of brushing your teeth;Cleaning bottles

Interesting thoughts. So, how much water do you need when rinsing out a bottle?

This probably won't help you, but I always rinse twice, no matter how much water I use.

Thinking back on it, I prefer smaller amount of water to get an energetic swish rinse.

The matter which you are trying to remove from your mouth should have enough water to become suspended in, and there is also probably an effect of the water's motion banging against food on your teeth and mouth and dislodging it.

That's what I am trying to figure out. I think the following are related:
1. Rinsing your mouth - guess 1/2
2. Rinsing a bottle - guess 1/2
3. Put cream in a bottle to make some kind of buttermilk, they say 1/3 full
4. Put rocks in a cylinder and shake until polished - guess 1/3 to 1/2. Maybe both work, maybe we are trying to minimize the time to do it?
5. Mixing a solution with different ingredients by shaking until mixed.
6. Cleanng a car with water seems to depend on the pressure of the water.
7. With a falling object - energy at the top is MgH (Mass, gravity, Distance), at the bottom Kinetic energy = MV^2/2. Are we looking for maximum energy, maximum momentum, maximum velocity, maximum force?

If the bottle is L units long and the Mass occupies X of those units then the distance travelled by the water is (L-X). The Mass is also a function of X. What is the function that we are trying to find the minimum or maximum of?

I think you have a point there.
Small amount of water will make you have that "energetic swish rinse"
and I think twice or thrice is enough