I soaked two of the coin mechs overnight for 8 hours and then scrubbed them with the brass brush this morning. I washed and blow dried them with a hair dryer afterwards. They came out amazingly great. Cosmetically, I wasn't really concerned about how they looked, but more of how they functioned. (It's just a bonus that they look great too.)
Originally, the return mechanism, when pushed in, was super hard to do. Now, it's like butter. It's just like new and coins no longer get stuck.
Thanks again for the tips.