Reddit mentions of Fast Blast Duster 10 oz. Can Air Removes Dust and Debris

Compressed Air.

But I think in this case you should get the serious stuff.

Fast Blast Duster 10 oz. Can Air Removes Dust and Debris

http://amzn.com/B005FMX712

Tip: Fixate the fans before blowing the dust out, otherwise they can induce current and kill your board.

Achoo

The old man is snoring

this air duster would be perfect because working on things you wouldnt have time for is great to do when its a rainy day

I use canned air. It works extremely well and has the added benefit of having a 100% chance of leaving behind no residue from cleaning products or damaging your 3DS.

This is relatively cheap. If I were you, I might try to see if you can find it cheaper locally though. Still, $3.99 isn't bad.

Amazon has some pretty cheap, lemme get a link real quick

Edit: here's the link; http://www.amazon.com/gp/aw/d/B005FMX712/ref=mp_s_a_1_4?qid=1409365571&sr=1-4&pi=AC_SX110_SY165_QL70

I don't know if the price would be the same or not though...

http://www.amazon.com/Fast-Blast-Duster-Removes-Debris/dp/B005FMX712/ref=lp_3012916011_1_3?s=pc&ie=UTF8&qid=1408302384&sr=1-3

Your CapsLock is stuck bro. Try some of this.

Cheap: Fast Blast Duster

Frugal: Metro Vacuum ED500

Just blow it with some canned air It's like $4 at Walmart. Blow some air through it and you're done.