Father refuses to drink liquid thickener. How do I manage this?

My dad has to have thickened liquid as well. For almost 2 yrs, I bought big barrels of thickening. Until, I realized that natural foods could be used instead. Everyday I make him shakes. See my profile for suggestions. He loves them. No side effects of constipation, waste, nastiness, etc. Apples, bananas, oatmeal can thicken foods.

Try smoothies with greek yogurt, silken tofu. I freeze ripened bananas then add frozen strawberries and blueberries. Even a fresh squeezed orange. I also add chia seeds. The yogurt or tofu and the frozen ingredients will thicken the smoothie.
For a water or juice thickener I use Simply Thick. It's completely tasteless and you can easily adjust the thickness.

Have you tasted/ tried water with a thickener in it?
Sort of nasty. Not the taste because it has no real taste but the combination of the thickness and the texture of the thickened water is a bit off-putting.
Thicken other fluids that you would normally expect to be a bit thicker. Fruit juices, yes a bit more sugar than water but it is fluid.
Thicken broths.
Thicken coffee, tea or flavor the water. You can use fruit juices or any of the water flavors that are out there (Mio is one that comes to mind) Even Crystal Light, Kool-Aid will flavor the water. I am not a fan of the artificial sweeteners but if the object is to get him to drink more if it works, great.
And your fluids do not have to come from just drinking.
Salads, fruit, soup, all have high moisture contents so you are getting fluid into him. And soup and stew can be thickened with mashed potatoes, beans or other vegetables. Oatmeal, Cream of Wheat, Grits will all get more fluid into him.
Dairy like cottage cheese, yogurt are also good options.
Jell-O or gelatin is not good because as it is eaten it becomes a fluid and may be aspirated.
Same with Ice cream.
Pudding is a good option.
Watch slippery fruits like peaches and nectarines as they can slide down the wrong way very easily (learned that from a frightening episode) Oranges are to juicy they are a problem.

I would try more natural food thickeners. Bananas and applesauce are great or even try different "butters" like apple butter or some other flavor. My mom wont drink her ensure if i add protein powder in it b/c she says its "gritty". I take follow the protein powder directions, mix it with either milk or water, add in frozen berries or bananas put it in a blender and then divide into silicone muffin cups or ice cube trays. I freeze the mix and then add that to her ensure in a 16 oz glass. it thickens the drink and adds extra protein for her. Supervision w/ choking hazards is key.

How thick does he need it to be? If he needs minimal (nectar) thickening then he may do better with regular beverages that are normally a little bit thicker like tomato and vegetable juice or fruit smoothies. Thickened coffee is weird, thickened hot chocolate not as much. And using a straw helps too.

Maybe a straw like mentioned below. Lots of "foods" count as a liquid like jello, pudding, ensure, smoothies, applesauce, soup and sherbet. Try to work with what he likes. My dad's last days he lived off orange sherbet and strawberry applesauce. Baby foods.

Have you by any chance taken your favorite beverage and put this in it. I NEVER in all my years of nursing found someone who could abide their liquids turned to sludge. I wish you luck. This is going to have to be something he could understand the reason for, understand the need for hydration, and agree to do despite how awful it is. Does Dad by any chance love a shot of anything? Because a few drops of Alcoholic flavoring was one way we got it down; it seemed to give odor more than anything else, of something they liked. Wouldn't want to suggest this for anyone who has history of alcoholism or anything, but it can work for someone who loved to have a highball at 5 p.m. And because you are administering basically drops, it might work. Check with doctor before doing this.

Try to get liquids into his other foods:  soup, watermelon, applesauce, etc.  It's not a complete solution but it will help.

Ice cream wasn't allowed in my father's dysphagia diet b/c it melts and becomes liquid, so I gave him a few tablespoons at a time; it was swallowed before it had a chance to melt.

One of his speech therapists suggested putting applesauce on foods to add more moisture to them.

Ballen, did his speech therapist give you a list of foods for each of the dysphagia levels?    Sometimes you can find in those lists foods which can be watered down, to increase the fluid intake.

I would try other drinks. My mother has been on thickened liquids since last year. She does not like plain thickened water alone. I do Glucerna homemade vanilla flavor shakes and thicken them up with avocado and banana. I put thick up in fruit drinks with no sugar added. I give her coffee on occasion and thicken it up with thick up. She will drink these beverages. When she eats I give her a spoonful of the thickened water after each bite of food. She will consume her water that way. It took her a few months to get used to it but does well now. I myself dislike the taste of thickened water but I tried the shakes and fruit drinks which taste better. Apple sauce with strawberries, soups such as pumpkin soup, carrot soup with cream, chowder, Chili, oatmeal, cream of wheat made with 1/2 water and 1/2 milk. I puree fresh pears, banana and pears, blueberries, yogurt mixed with berries. I would google pureed foods and beverages to get more ideas. I was told never to use a straw by her speech therapist because drinking fluids too fast could cause aspiration. I spoon feed my mother her liquids and pureed foods. Barnes & Noble has some cook books on pureed foods and beverages. Good luck.

Imho, juice with pulp is better than no liquid at all.