Salad With A Side Of Shampoo?

A few weeks ago my friend Nicole, who is also my hair stylist, gave me a dollop of shampoo to brighten up my blonde locks because she noticed that the color was fading a bit. I was at her house when she extracted my sample from her personal shampoo collection, so all she had for a container was a tiny Tupperware. You  know which kind I am talking about, the small, round fella that you would normally put salad dressing in. After I used up the shampoo, I washed the Tupperware and put it in my cabinet at home and forgot about it until today. I wanted to take a salad to work for lunch, so I prepped the lettuce and other veggies in a big Tupperware, and put my salsa (my type of salad dressing) in the littlest Tupperware I had in my cabinet....I'm sure you can see where this story is going. I took a big bite of my salad at lunch this afternoon and it was like I had squirted the shampoo directly into my mouth. Apparently 'that taste' doesn't come out of Tupperware, (or my mouth for at least a few hours for that matter).