In reality, nothing helps to dry the device out, because the water leaves impurities behind. All devices, even those marketed as waterproof, are only really water resistant to some extent.
You really need to open the device (or have it opened) to inspect for liquid inside. Most repairers wouldn't touch it beyond for data if there is water inside, as water damage can be progressive. So you should be aware if any trace of water is found, it could actually get worse as time goes by without proper treatment.
The speaker is a fairly exposed part however, so there's a chance liquid has penetrated the speaker, and gone no further. It is possible if this is the case drying it may "help", but its also possible a replacement is required. Given that it happened days ago and is still an issue for you, i would assume the latter at best.
In any case, i would highly recommend opening and inspecting the device thoroughly. It would be a shame to use silica, rice, heat, and find it does correct your speaker issue, only to find your phone doesnt turn on in a weeks time due to unseen corrosion somewhere else.