The Power of Apple Cider Vinegar for Rust Removal

you could line a crate with a garbage bag and use that as a dip container, just keep the block winched up. you can do hoods too, just get a kiddie pool and a fountain pump. Pump the juice through a sprayer and let it run over the hood.
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I just put your idea in to motion. I put a fountain pump on the top of the block submerged and ran a hose down through the cam tunnel halfway through the block. So the water is now circulating through the block.
Hopefully this will be more efficient than just sitting there soaking.