I once dropped my phone into a tub of ganache that I was making that I should note (just in case) was a bit smoother than a usual ganache and had too much chocolate (I was following a rubbish recipe). I have left it for 8 months now and only now have I found working headphones that fit into my jack that aren't a friend's. I tested them with my Chromebook and they were really good and then put it in my phone jack to listen to songs. It wasn't working because of the ganache. I found this weird though because most of my headphones were fine.
Headphone jacks are usually quite resistant to shorts, unless there is output on them.
If it is possible to disconnect the battery, I would probably get some isopropyl alcohol (also known as isopropanol), carefully pour some into the jack and use a needle to scrub out what didn't come out by itself.
Why isopropanol? We use it at work to clean printed circuit boards and it works well. It is safe to use in cleaning electronics.
If you cannot take out the battery, the above might work as well but it will probably damage your phone.
I'd take toilet paper (that sucks up liquids well), roll it up, then heat up the jack with a blow-drier and then let the toilet paper suck the liquid out.
You'll of course need to take care not to cause more damage then you already have by:
- overheating the phone with the blow-drier
- leaving toilet paper in the jack, that you can't get out
When you put the phone jack into the hole, you smashed anything that was plugging the hole into new places that aren't going the be accessible to cleaning from the outside. You might get luck cleaning it out with a vacuum, but not likely.
You'll have to take the phone apart to remove it. This can be tricky and should be done very carefully with reading instructions or watching videos about your exact model. Some phones require a very specific disassembly order and some require special tools. Once you get in there, you might be able to gently remove some of the dried material with a toothpick or a toothbrush. Some might be harder to remove, so using a minor solvent and a cotton swab might work. Just make sure that there's no solvent or cotton remaining when you close up the phone and turn it on.
Also, you'll still need to clean out the receptacle itself. You can try flushing it out with the solvent, when you still have the phone apart. You can also try gently using a toothpick to knock out pieces.
I'd avoid using paper products, since paper towels tend to leave fibers behind and toilet paper is designed to disintegrate when it gets wet. And regular copy or notebook paper likely won't soak up liquids like you want.
The other option is to take it to someone who does cell phone repair professionally. It's not a hack, but it's better than destroying your phone.