How to Make It
Combine cucumbers and onions in a very large Dutch oven; sprinkle with salt, and add water to cover (about 18 cups). Cover and let stand 3 hours. Drain well. Rinse with cold water.
Combine vinegar, sugar, mustard seeds, turmeric, and cloves in Dutch oven; cook over medium heat 5 minutes. Add cucumbers and onion; bring to a boil. Remove from heat.
Pack hot cucumber mixture into hot jars, filling to 1/2 inch from top. Remove air bubbles; wipe jar rims. Cover at once with metal lids, and screw on bands. Process, in 2 batches, in boiling-water bath 12 minutes; cool. Chill pickles before serving.