I've got some I've been using for two years. I give them a good rinsing and a spray when I've poured them and a rinsing with sanitizer when I'm bottling. Some of mine were looking a bit grubby so I did a proper bottle wash with a brush, warm water and Oxy and they came up as new. When I see them in any way mis-shaped or if they are dented at the bottom where nasties can hide then they get binned.