Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Disappointed

Some workers left some mystery stains on my concrete driveway, figured they were gas or oil. Tried some Simple Green didn't work so bought this stuff. I've used it 3 or 4 times so far and if it had any effect, it's pretty minor.However, I got some lubricating grease on my hands the other day and tried this for that. It did help in that case. So it's not totally useless, just not the magic potion I hoped for.