Place zucchini & onion in a large bowl. Sprinkle with salt & toss to coat. Add water to cover; let stand for 2 hours. Drain; rinse thoroughly.
In a 6 - Qt. Stockpot, combine remaining ings. Bring to a boil. Stirring to dissolve sugar. Reduce heat; simmer 5 minutes. Add zucchini mixture , return to a boil. Stirring occasionally. Reduce heat. Simmer uncovered 4-5 minutes. Or until heated through.
Carefully ladle hot mixture into 6 hot 1 pint jars.leaving 1/2" headspace. Remove air bubbles. If necessary. Adjust headspace by adding hot pickling liquid. Wipe rims. Screw on bands.until fingertip tight. ( get your lids ready as directed on the box).
Place jars into canner with simmering water. Ensuring they are completely covered with water. Bring to a boil. Process 10 minutes. Remove jars & cool.