When to use dual agent for house purchase

I heard of folks talked about using dual agent to secure a hot deal, but not sure if it's a good idea to use dual agent to negotiate for a good price. Will it be better to use a buyer agent or dual agent if the goal is to secure the deal and also negotiate for a good price. Does anyone have similar experience? The property that I'm interested is a bank owned. The listing price is a little over-priced. Thank you in advance for your advice.