Seltzer water worked for me to cut the mucous the first time.
I found that the plain generic Safeway brand in the small cans worked best. The big bottles lost their fizz after opening and without the swishing bubbles did not cut thru the mucous. Although they are all carbonated water, I had issues with club soda and tonic water which burned my sores. Seltzer contains no added ingredients or flavorings, club soda contains additives such as table salt, sodium bicarbonate, or potassium bicarbonate and tonic water has quinine and sugar.
After the recurrence, the mucous was so bad, the hospital arranged a rental suction machine for home use.
Can't hurt to buy a six pack of seltzer, you can always drink it if she does not like it
Charm