While I haven't travelled to the US since pre-2001, I have travelled in Asia quite a bit over the years and recently went to Hong Kong and Malaysia. I live in Singapore and Changi Airport is pretty good when it comes to security. I don't use a ziploc bag for my LGAs but I do use a zippered clear plastic pouch. I've never been stopped or checked for it even though I don't take it out of my carry on. In fact on my recent trip the only thing I got stopped for at security was because I still had water in my water bottle.

Oh and if it must be a ziploc bag and only a ziploc bag, why is that companies that see refillable travel containers usually give you a clear plastic pouch which is apparently 3-1-1 compliant?