Phone sprayed with hand sanitizer results in faint speaker

Because of various family health problems, we're visiting the hospital very frequently now and so, because of the covid situation, we're using the hand sanitizers provided there whenever we enter and leave the building. My grandma usually also uses it on her phone cause she's using it inside and recently, after one of such actions, the speakers in her phone (Nokia 2.1) suddenly started being really, really quiet. It's not like she dips the phone in the sanitizer and she's used it on the phone a lot of times already but this one time was some kind of unlucky, it seems.

I opened the back cover, shook out some of the liquid, we tried using blow dryer on it, the sonic toothbrush trick (holding the bristles over the speaker cover), I ran all the apps which claim to use frequencies to remove fluids from your phone speakers, we kept it in a sealed container with rice - but to little avail.

All this allowed the call speaker to become functional again but the main one which plays the ringtone and which handles the loudspeaker mode (which is something grandma uses a lot regretfully) is so quiet that you need to keep it right beside your face to hear _anything_. What else can we try? Because of covid, taking it in for repair isn't really an option so I have to refrain to guerilla methods.