IPhone 5s one speaker won't work?

I dropped my phone in the toilet and haven't put it in rice while there are no other visible signs of water damage besides the one speaker not working

There's likely still water in your phone and the more you use it, the more it will move around eventually damaging things. I've talked with the guys at TekDry while they dried my boss' iphone 5s (twice) and they said they frequently see people come in with phones that got wet, later worked, and eventually had more and more problems. If you let it get to that point, drying it won't help because the phone has been corroding all that time. Getting it completely dry as fast as possible is vital if you don't want to see further damage.

for your best chance to save a wet electronic device…
1. Do not turn it on or try to charge
2. If possible, remove the battery
3. Contact TekDry - they have a patented process that will remove all of the water for sure - typically in about 30 minutes, without taking it apart.

With rice or desiccant, it takes much longer (days) and you don't know if/when your device is dry. Each time you try to power it on to find out if it is dry, you do more damage to your device. Plus while your phone sits in rice for days your device continues to corrode and you get rice particles inside your phone creating more issues.

Rice (or silica gels/desiccants) does absorb water, but only when in direct contact. Rice outside of your device will not draw water from within your device. If the humidity is extremely high it is possible rice will draw some water from the air, however the humidity around your wet phone is not going to get that high. So while popular to try, rice does not actually do anything to dry your phone. You might think it did if your phone turns on but there's likely still water in the phone that can continue to cause damage.