The Camden Harbormaster posted on Facebook:
Daily Def: “SLUSH FUND”-slush was the unpromising name for fat scraped off the top of the barrels of meat. The crew found it perfect for greasing masts to make sail hoisting easier and for preserving leather fittings. The cook, unhappy about this, would secret it in his ‘slush fund’. It was a prerequisite so far as he was concerned. He sold it ashore, mostly to candle makers and people in the fish and chip trade.
Who knew? Well, I did, sorta. The schooner Mary Day gets her masts slushed a couple times a year. Usually, it’s the youngest (lightest) member of the crew who gets outfitted head to toe in disposable gear, then strapped into a boatswain’s chair (boson’s chair, really just a board strung between some rope). Then this person is hoisted to the top of the mast with a bucket full of slush. These days, slush is not meat grease but Vaseline petroleum jelly. They start at the top, smearing Vaseline all over the mast. When a section is finished, they yell to the deck, where someone standing by lowers them a few feet.
Here’s Madeline slushing the mast: