You have to be careful dumping water on a "real" module. The "fake" china modules, the transistor is fake. But on a "real" module, the transistor is insulated from the case, by the voltage on the coil NEG primary. When operating, this is above ground by the amount of the coil primary pulse, over a hundred volts. If there is dirt/ corrosion around the case, it will short and may not generate spark. Years ago I had that trouble, SB Mopar in my old Landcruiser. playing in snow/ mud/ water would cause it to miss badly I finally moved the coil and box up under the dash, and ran the coil wire out through a grommet in the firewall