That can be frustrating. I dealt with something similar with my older cousin when she had dementia. Initially, I tried to care for her in her home, but it became too much for one caregiver in the home. I would talk positively about bathing and promise all the good things that would happen afterwards, like a drive, her favorite music video, ice cream, etc. She would whine and protest, but we got through it. Later, she would refuse help bathing in the regular assisted living facility. Resistance to care in general became a problem and then wandering. So, I had her moved to Memory Care. There, they knew how to manage her care and she got 3 showers a week. No problem. The staff are trained professionals and they did an excellent job of managing her care, including bathing.

An aversion to water is common with dementia. Many experience it. For some people it might fade.

I hope you can find help. Some people get outside help, like a bath aid. We got my dad that, but he refuses to allow it. So, I’m looking at facilities for placement now.