The best solution IMO is to disassemble it (not only remove cover, battery etc) as far as one is able to, then, put into silicon gel and seal in airtight container (was mentioned in link I provided). This way, silicon gel won't reduce atmosphere humidity (due to airtight container), but suck it from N900 parts (also through air between silicon gel and N900 - this way, N900 dries faster, little amount of air in airtight bag/container act as humidity transport).

Don't listen to gadget websites - they don't have a clue, Without using airtight container, what they expect, if not reducing room atmosphere humidity? :/

/Estel

// Edit

It's good practice to have some silicon gel just in case - it's not expensive, and after being used, it can be "regenerated" by putting it into 120 C degrees (oven) for 2-3 hours.