Possible Clues:

• Respecting air control
• Engineers wanting stock control
• Hold back and relax before shower
• Bottle the remains of the water
• Trainers trying to hold back
• The others rushed outside: I hold back
• Keep the star in control with a rein around it
• About to take stock, being moderate
• Check in after the arrest goes awry
• What's left is not so fine, so keep it back