Is there any reason to not just soak the wood chunks to raise their moisture?
There are several factors that impact the moisture content of wood. Relative Humidity where the wood is stored/located is the most important factor. Temperature also has an impact, but not nearly as great as humidity.
Essentially, like most water absorbing materials, the moisture content of wood is directly related to the relative humidity. The following illustrates the relationship between wood moisture content and the relative humidity of the environment where the wood is located. The "EMC" is the equilibrium moisture content of wood.
0% RH = 0% MC = 0% EMC
30% RH = 6% MC = 6% EMC
50% RH = 9% MC = 9% EMC
65% RH = 12% MC = 12% EMC
80% RH = 16% MC = 16% EMC
99% RH = 28% MC
I've soaked wood chunks, wood chips and saw dust on a few occasions. You have to soak wood chunks for a long time to do much good. Sawdust absorbs water fairly fast. The thicker the piece of wood the longer it takes to absorb sufficient water to impact the moisture content of the whole chunk of wood.
I don't think soaking bigger wood chunks is worth the effort. Moisture content is really only important when it comes to burning it.