My 2010 Ex35 headlight is getting moisture in it which is causing fogging. I have been told that the EX35 headlights do not come apart so it can not be fixed or cleaned and my only option is to buy a new headlamp. Is this true? Are there any other options?

If you don't mind messing around a bit, you can try removing the low beam bulb dust cap and all the bulbs from the headlight, and park the car with the offending headlight in the sun for a few hours. I think you can also use a hair dryer to help get the moisture out if the weather isn't that warm. If the condensation goes away and doesn't come back after a couple of days, the seals still might be OK.

I'm not sure who told you that the headlights cannot come apart, but whoever they are, they're technically wrong. Sounds like something that a dealership would say. Instead of purchasing an entirely new headlight assembly, the other and more likely cheaper option is to remove the headlight assembly from the vehicle and use the "oven" method to help break the seal between the lens and body of the unit. Once the lens and body are apart, they can be resealed, again using the oven method.

Forum member jakenbake has done this to the headlights on his EX. See here:
exchanging-halogen-headlight-lens-with- ... 03497.html

And if you're not comfortable doing the job yourself, look for a shop in your area that specializes in custom automotive lighting upgrades. Headlight removal and disassembly is something that they would be doing on a daily basis.

For some reason my headlights are dusty on the inside. I'd rather not have to bake them just to clean the dust out. What about removing them and the bulbs, then hosing out the inside with some reverse osmosis water to try to avoid water marks? De-ionized water would be even better, if I could get my hands on it.
Thanks,
Jon

Double check that your dust caps on the back of the light are screwed on correctly...that may be where the dust is coming from. Also, I wouldn't spray water in there. I would take out the bulbs and blow compressed air in there. The dust should come out.

I'll check the dust caps and try air first. Thanks.