Honda's direct-injection engines are less susceptible to carbon buildup than other brands. By design, the combustion chamber's injectors spray onto the backside of the valves. 
If you have access to a boroscope, you could inspect the combustion chambers. Perhaps, even the intake tract.
We own a GDI car that requires yearly cleaning of the intake. We use BG44k.
Amazon.com
All the above said, I agree with pulling a spark plug when the engine doesn't start. If it looks 'good' (light gray electrodes, no obvious difference between cylinders in carbon or gasoline, proper gaps, etc) they can be re-used The Iridium plugs used by Honda should last MUCH longer than 85K miles, though. One user here reported his car ran fine on original plugs at 200K miles!
If you have access to a boroscope, you could inspect the combustion chambers. Perhaps, even the intake tract.
We own a GDI car that requires yearly cleaning of the intake. We use BG44k.
Amazon.com
All the above said, I agree with pulling a spark plug when the engine doesn't start. If it looks 'good' (light gray electrodes, no obvious difference between cylinders in carbon or gasoline, proper gaps, etc) they can be re-used The Iridium plugs used by Honda should last MUCH longer than 85K miles, though. One user here reported his car ran fine on original plugs at 200K miles!
