Downhole vibratory tools that use fluid flow to reciprocate a rotor in a vibration chamber and associated methods and processes. In a first illustrative embodiment, an elongated external housing allows connection to a drillstring, behind a downhole drill. From a top sub, fluid flows through a first flow plate and spiral flow chamber to enter a central vibration chamber in a spiral direction and exits the vibration chamber through a counterpart second flow plate and spiral flow chamber. A rotor is disposed in the vibration chamber. The spiral flow through the vibration chamber causes the rotor to reciprocate around the vibration chamber, thereby creating vibrations that are transmitted to the drillstring. Methods of use include deploying the vibration tool to improve rates of penetration and enhances reach by creating resonance vibrations against the wall of a wellbore to effectively break static friction.