My DS carried on 2 large bottles, 1 Aosept and 1 Saline, on our most recent trip. No problems at all, in Orlando he forgot to get them out of his backpack but TSA just took them out (they were in a large zip-loc bag) and very nicely reminded him to always put the bottles in a tray for screening. The TSA agent just ran them over something and handed the bottles back. In Huntington, WVA at a very small airport that Allegiant flies out of, the TSA actually tested both his bottles with some sort of strip. They also swabbed his carry-on and patted him down. That has never happened to him before but the Huntington airport is so small I don't think TSA had anything else to do.