My father misses the toilet and urinates on the floor. What I do to help his aim when he pees?

Let him pee into the tub or shower, then run the water to rinse it out.

Have him sit. Someone on the forum had their parent clean up after themselves and they stopped. This will be hard if Dad has Dementia/Alz.

It took us a long time to convince my husband to sit. He has mobility issues and it was just easier to wipe it up myself than risk him bending over to wash the floor and falling. My son was actually the one who told him he had to start sitting. I got to the point I put newspapers around on the floor.