However, most containers for condiments are the perfect shampoo bottle size. Instead of tossing them into my recycling bin, I ran the jars through the dishwasher a few times (on top of initially rinsing them out) and filled them up with shampoo. Most bulk-sized shampoo containers come with a hand pump, which makes things a thousand times easier to transfer the shampoo to the smaller containers (although it does make you feel like you're playing a Minute to Win It game).
Most labels these days seem to be superglued to the container. You can either attempt to get them off with a scrub brush and Gu-Gone, or you can go down the smartass path like myself and just go at the label with a Sharpie.