A pressure washer with hot water would work,,, even a car wash, with a hand wand system. Don't soak the wood too long or it may swell a bit. The metal is easily cleaned in a car wash too. The high pressure hot water really works on the cosmoline. Small parts should NOT be pressure washed.. Always finish with the hottest water available. It will heat the metal and allow it to flash dry.. Be sure to oil after as the bare metal will want to rust quickly..