so i just put my shampoo through without a bag, and they don't notice it. they do notice my bottle of water. it's just so strange to ban water that it slipped my mind (i'm no chemist. maybe it's a justified security measure. but it is strange to live in a world where water is a security issue). i asked if they could pour it out and give me the bottle back, but the guy just walked off without a word. i waited a while and fortunately he came back with my bottle. he put it through the scanner, empty. i guess you can never be too careful with clear plastic bottles. he didn't say anything so i asked if i could go now, and i could.
for the flight back i brought a ziplock bag. unfortunately that meant they noticed my shampoo, and then threw it away for being too large (6 oz bottle not 3.4 oz.). it was only half full.