Injection drug users (IDUs) contaminate preparation materials with blood-borne pathogens by using syringes as measuring and dispensing devices. In collaboration with IDUs, we developed a preventive intervention consisting of four new preparation practices aimed at avoiding the use of syringes in the preparation, and reducing the contamination of the materials. This report describes the results of a pilot trial introducing the new practices to ascertain their adoption potential and their potential efficacy in reducing contamination. Participants comprised 37 active IDUs among whom the new practices were promoted during 16 weeks. In addition to self-reported behaviors, the study collected cookers and plastic caps from shooting galleries and tested them for the presence of blood residues. Adoption rates were: (1) cleaning of skin area with hand sanitizer—65.6%; (2) directly pouring water with a dropper into the cooker—56.3%; (3) drawing drug solution with a preparation syringe and syringe filter—34.4%; and, (4) backload rinsing syringes—53.1%. Rates of blood residues detected in cookers and plastic caps were 41.7% prior to the trial, 28.6% at week 8, 24.6% at week 14, and 12.0% at week 18. We believe the results of the pilot trial are compelling and suggest that this intervention merits further formal testing.