If shampoo I bought doesn't work for me at all (allergy or something) I use it when hand washing sweaters :P
Everyone does that, whether they admit it or not. Also, when I'm running out of shampoo I put water in there and shake that shitt up! And voila, you gots shampoo for the next day! xD
You are a toilet
If I don't like it, my husband inherits it.
Even if I do like it, my husband inherits it when it's about 1/4 full. I haven't actually finished off a bottle of shampoo myself in years.
The same goes for boxes of cookies, cereal, ice cream bars, etc. Of course, I don't wash my hair with those. I eat those. Well, you know what I mean. I think.
I have used shampoo for soap, but only when I've run out of soap. lol
If I REALLY don't like a shampoo, I'll give it away to someone I know.
Edit: To someone who either knows they like it or wishes to try it. Since I already use ONLY 100% botanical shampoos, my only reason for not liking a shampoo is because it's "thin", I like a thick shampoo.
I do that anyway, stick to cheap anti-dandruff shampoo myself.