Am I able to remove petroleum jelly from my speakers?

I had an accident with my iPhone 4S. What happened was that, my Vaseline containers lid fell off, and I put my phone in my bag, facing upright vertically and It went straight into the container!!! So my speaker and microphone aren't working effectively as it sounds really low, so that have to use the headset instead. Whats more is that I tried using my blow dryer so that It could melt the Vaseline and I just want to know if this is a problem that I can fix, and if not should I just take it to the store? Someone please reply back.