If using anchovy fillets, it's a good idea to smear them into a paste using the side of a knife to break down any bones.
+Using less mayonnaise makes for a thinner dressing, and in my opinion less mayo flavor is better.
+The onions will pack a lot better, and ferment more if they are sliced super thin. Use a mandoline if one is available.
+Add some spices for extra taste - People recommend celery salt.
+Mix additionally after bottling to ensure proper coverage.
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