Mike Pinto from thesmartguitarist.com demonstrates his custom Wet Blender pedal, built into a Dunlop Volume(X). The pedal has four jacks: input & output, and send & return. Connect a reverb or delay to the send & return jacks, and use the Wet Blender to blend the wet signal (reverb/delay trails/repeats) into the dry signal, which remains entirely analog & unaffected by the connected wet pedal.