No ideas for DS but if it were me - I'd be sipping on some JEZYNOWKA - LeRoux Polish Blackberry Brandy - I've not been able to find it locally - usually have to grab my bottle when I go to NY.
Don't know about for a 9year old, but for me, the only way I got rid of my cough was I took a day off from work, started at 6am and drank a 2 oz shot of Gentleman Jack, straight. Now every night before I go to bed, I have a 2oz shot and never wake up with the cough. If you heat Dr Pepper, try to get the kind still made with sugar, not frutose syrup.
HE HAD PNEUMONIA! Tell me how we could be at the doctor on Tuesday and have NO strange sounds in his lungs but today he has pneumonia?? So, time to pull out the big antibiotic guns. We did catch it quick though, thank goodness!