Is it OK if I Always Use a Hand-rub Instead of Soap and Water?

No, you cannot always use hand-rub instead of soap and water. There are very specific uses for both of these products. The CDC states that you can use a non-antimicrobial or antimicrobial soap and water when hands are visibly dry or contaminated with blood or other potentially infectious material. If hands are not visibly soiled or contaminated then you can use an alcohol based hand rub following the manufacturer’s instructions.

Source: Center for Disease Control and Prevention (CDC), Infection Prevention Checklist for Dental Setting: Basic Expectations for Safe Care, Page 6, https://www.cdc.gov/oralhealth/infectioncontrol/faq/hand.htm