Typically a "round" of chelation is some number of days, for example, 2.5 or 3 days for Cutler's classic protocol.
Chocolate can be tricky with the sugar, phenols, etc. I like the extra energy and alertness but for many years I would end up on an energy roller coaster. I'd be too hyperactive and then my mental energy would crash into lots of brain fog.
I had to learn to support energy and mental alertness in other ways.