Devices and methods for electrolytic electrosurgery wherein a detector is located proximal to an active electrode on an electrosurgical probe, optionally disposed between the active electrode and a return electrode, the detector detecting at least on parameter relating to electrolysis. The detected parameter can include pH concentration, conductivity, impedance, ion, concentration, electrolytic gas consumption, electrolytic gas production, pressure or sound. The detected parameter can be employed in control systems to control systems to control activation or operation of the electrosurgical probe.