Do yourself a huge favor and stop buying supermarket salad dressings. They are full of unhealthy seed oils, sugar, and preservatives. Even the premium "healthy" brands are likely to thin out the olive oil with canola or soybean oils.
More on why you need to stop consuming seed oils is here.
The first video on this page explains how bad seed oils are.
I searched high and low for a good container to mix up and pour my own salad dressing. I like a good red wine vinaigrette with some Italian herbs and spices. I found this OXO Good Grips Little Salad Dressing Shaker that works great for me. They claim it is dishwasher safe but with the o-rings they use to seal it, I just don't trust the dishwasher not to wreck them over time. The base can go in fine, I soak the top in soapy water in the sink. I store the dressing in the fridge and take it out ahead of time to let the olive oil warm up. I've even nuked it for 10 seconds if I forget to take it out. It's available in black, green, and a large size as well. After pouring leave it up for a minute to allow any remaining dressing to drain back inside. If you're fussy like me wipe the tip with a small piece of paper towel before closing.
