For this particular endeavor, opt for small pickling onions to achieve the desired results. Begin by delicately removing the skins from the onions, taking care not to cut into them. Proceed by thoroughly washing the onions, preparing them for the subsequent step. Engage in the process of wet-brining, allowing the onions to soak in a brine solution for a duration of 24 hours. Once the designated time has passed, drain the brine, followed by a thorough wash and dry of the onions. Prepare the jars for their flavorful contents, carefully placing the onions within. It is then time to elevate the taste profile by filling the jars with a cold, spiced vinegar solution, ensuring the onions are completely submerged. Seal the jars in the customary fashion, securing their contents for the journey ahead.