Wash and thinly slice the cucumbers, Leave skins.
Peel and slice the onions. Combine the cucumbers, onions, and salt in a glass or ceramic bowl.
Let them stand 3 hours to extract the moisture.
Rinse and thoroughly drain and dry the vegetables well . Combine the remaining ingredients and mix well until the sugar dissolves completely, about 10 minutes.
Pour the cucumber mixture into clean freezer containers, leaving 1 inch of headspace for expansion.
Cap and seal. These will keep up to 1 year in the freezer.