I had an infrequent cough after testing negative and flying home. I wanted to take some cough syrup with me in my carry on. I had the syrup from Centrum Apotheke, but needed 100ml bottles to transfer into plastic quart bag. I searched all over Galeria in Frankfurt but could find no such bottles until I was in liquor section and found 95 ml Vodka bottles. I bought three and filled them. At security my plastic bag went to secondary screening lane. The checker looked at my bag with brownish syrup in the Vodka bottles and chuckled and gave me the bag. Vodka bottles were cheap, about €1.29.