i just put the thin nozzle right up against the microphones and speakers. it did the trick.
I dropped my iphone into a plastic bag which had an accidental oil spill in it. It was covered in a thick layer of oil and after wiping off the oil the speaker would only play very softly. I found this site and a day later I bought a can of compressed air for $2.50 from Officeworks and sprayed it into the speakers. Oil immediately started seeping out from the side of the phone and it started working just fine again. Thank you so much for the help! I wonder if it still needs a thorough clean from the inside though. I don't know how to open the phone. Will try Apple and see if they will do it out of courtesy as it is working.