Pilot Reported The Airplane’s Braking Was Ineffective Due To The Runway Being Wet And Recently Rolled Analysis: The pilot reported that while landing on a wet grass runway, the airplane touched down “a little long.” The pilot was unable to stop the airplane, and it departed the end of the runway surface into an agricultural field. He then attempted to avoid the agricultural vegetation off the end of the runway by turning the airplane to the left; however, the airplane entered a skid and subsequently impacted the vegetation which resulted in substantial damage to the fuselage.