Dear Madam,
Hand sanitizers are usually employed in food industries to reduce the load of coliform bacteria. Coliform bacteria is visible in hands when you dont wash the hands after going to the washroom, or when you handle raw materials which has fecal contamination. Fecal contamination might occur in RM from the agricultural fields or during transportation.
If its general bacteria that you are looking into then, you must be knowing that we humans are the reservoirs of bacteria, you dont need to go anywhere looking for bacteria.
Either you can go with different antibacterial agents (like phenol, chlorine, or commercially available dettol, lifebouy, soft care plus etc).
or you can pick up one of these and study their effectiveness at various concentrations, or time limit of its effectiveness or the contact time while washing etc.
Its a wide range to choose from..all the best on the project