I recently took my Rescue Diver/First aid/CPR class. The American Red Cross was fastidious in using alcohol and wipes/breathing barriers when practicing CPR, etc. What is the chance of contracting hepatitis c or the like from buddy breathing? For the most part you are taught to give up your primary and breathe off your backup when sharing. Have any of the agencies changed any policies or trainings because of concerns? Or the other question that came up, was in the amount of post use cleaning that goes into regulator rental, etc.