I remember reading an Army report about a "smart" pilot who was returning to base in his Gazelle. He knew the engine would need a compressor wash back at base but spotted a crop irrigation spray rig in use, in a farmer's field. He decided to use the spray rig as a giant comp wash and hovered under it.
Great idea...or it would have been if he hadn't flamed the engine out, hit the ground hard and bent the undercarriage!