I've found slosh balls are a great tool for developing many different qualities. They also work very well with groups.
They can be used for improving conditioning, stability, strength or even team building. I've found using relays very effective for conditioning and team building.
Because Slosh Balls move erratically, each exercise engages many muscle groups. This makes them ideal for developing functional strength at lower reps and great for conditioning at higher reps.
Slosh balls are like possessed medicine balls. They work in the same way that aquabags do, the sloshing water is the resistance and creates a destabilising force. The more you fill it, the heavier and more stable it is, but if you fill it to around half capacity the destabilising force will be at it strongest. This spherical shape allows for slightly more random movement of the water, compared to the aquabag which has more of a cylindrical shape. The water can move freely because the open space in the ball is easier for the water to access. The water is free to react off its' self with the spherical shape.
Because of its spherical shape, the water will always rush back to the lowest point of the ball (the centre of the bottom) to level itself out (gravity determines this), so during a quick straight up - straight down movement, water will part from the centre in opposing directions then come crashing together when these 'parts' collide as they rush to compete for that lowest point, they create an erratic, unpredictable and unstable environment.
The large slosh ball can be loaded with up to 40 kgs of water, the medium up to 25kgs and the small up to 15 kgs.
Relays
Beginner relay:
8-15 squats bear hug grip, Carry Zercher grip (arms under the ball) 20m-30m.
Pass the ball to the next person if in a group situation. Or rest as needed for one person.
Intermediate relay:
5-10 squats and press, bear hug grip walking lunge 10-20 rep ( 5-10 on each side), Carry Zercher grip20m-30m
Pass the ball to the next person if in a group situation. Or rest as needed for one person.
Advanced relay:
5-10 cleans, bear hug grip walking lunge 10-20 rep, Carry bear hug grip 20m-30m, 5-10 Good mornings zercher grip.
Here are some great conditioning exercises if you only have a small amount of room.
The man maker combo: Burpee, clean, squat and press.
Slosh ball complex: clean, squat and press, overhead lunge forward, side lunge.
Cleans, squats and lunges are great whole body strength builders. Using a bear hug or zercher grip really works your upper body. You can place the ball on one shoulder if you really want to work your core.
3-6 reps or 3-6 sets shooting for around 15- 30 reps per session is a good start for building strength with the slosh balls.
When you are cleaning the slosh ball ensure that it is inside your feet.
The clean can be done with a straight spine, or with a little flexion. Be aware flexing your back is more stressful on your spine, but you may need to flex a little to get a strong grip on the ball. This style would be really useful for someone that needs to be strong in spinal flexion, like a grappler, but if you don't need to then a straight back it more advisable.
Some more great combo are the Lift & Lunge and the Rolling Complex