I would like to know the standard operating procedures for cleaning out shotcrete hoses with air and/or water and, in particular, how to keep the hose from whipping when using air.

Shotcrete hoses can be cleaned out using either water or air. In many instances, the site conditions make cleaning with water not feasible. When cleaning with air, the free end or discharge end of the hose should be secured to something to ensure that the hose does not whip as the material and cleaning ball or rag discharges.