A pre-treatment of cuttings with a powder-based growth substance is one of the most common methods of instigating cuttings to generate roots simultaneously and uniformly. Because of its special compound, powder has a slow release effect. Many plants may show a better reaction to this slow release of active ingredient than they would do to the faster absorption from a solution.
To select the rooting powder you need please check the Rhizopon rooting guide by clicking this link: RHIZOPON ROOTING GUIDE.