You bring another interesting point to the discussion. I’d never heard of thickened water.
Since I have Hypothyroidism I have issues swallowing large pills or some times even water in a normal drinking mode, I sip it or I choke. And am aware of the health issues that the disease causes, even if mine is not one of the major types, just low functioning thyroid. Boy can I tell you if I don’t take the Name Brand and take it right on a fasting stomach, I pay the price for it. It is not a commonly understood disease and is what is termed a ‘hidden’ disease. I’ve had it over 25 yrs so other health issues it causes are popping up now.
I’m not sure I would have known about “thickening” water except for my job. I don’t know where you purchase it, or what it costs .. or if your doctor has to write a prescription for it.
However, I hope it is something you can use to help you with your issue.