True.
I have seen pictures of culture plates, where they took a culture from nurse's hands after they washed with an antibacterial soap, and another one where they used a Purell type gel. After a few days, the plate where hands were washed with soap was teaming with bacteria, while alcohol gel one had barely any growth on it.

In my hospital they have now changed the phrasing of signs in the bathrooms. They say you can wash your hands with soap and water OR use the alcohol based gels