If you have to shake those bottle only once, do it manually.

If you have to do that every day, then it is more convenient to build an "agitating" rig. Attach a platform to 4 wheels, eccentrically (like a cart, but with wheels not centered). The eccentricity doe not need to be big - maybe 2-3 cm should be enough. Secure the bottles on the platform with another piece of board on the top.

Rotate one wheel - the entire setup will rotate up-dow, in a circular motion. To break the circular movement in the bottles, alternate the rotation direction.

To make it easier, attach a small motor. It will do the rotation for you, much faster.

If you have to shake those bottle only once, do it manually.

If you have to do that every day, then it is more convenient to build an "agitating" rig. Attach a platform to 4 wheels, eccentrically (like a cart, but with wheels not centered). The eccentricity doe not need to be big - maybe 2-3 cm should be enough. Secure the bottles on the platform with another piece of board on the top.

Rotate one wheel - the entire setup will rotate up-dow, in a circular motion. To break the circular movement in the bottles, alternate the rotation direction.

To make it easier, attach a small motor. It will do the rotation for you, much faster.

The violet spots are the fixation points of the wheels and are in the center of the wheels. The red spots are the spots where the platform attaches to the wheels - and they are off-center.