As others are saying, Ovenpride, it's relatively nice and chill. You can use a sealed bag, with the part sealed inside in a good lug of the product, and then work the liquid in/over the part with your hands through the bag, or just use a suitable tub and squirt a little liquid over the part and give it a few minutes. Do use some gloves when taking the part out though. When you think the liquid's done it's job just rinse under the hot water tap. Also, if you need the liquid to get into any hard-to-reach areas just use something small like a cotton bud/paintbrush/toothpick or similar:
Works every time, and never had any issues. Though, don't walk away and forget about it for too long, as if left for an overly long time it may start to discolour/eat away the base metal.