Will not bathe or take showers, any advice?

https://www.agingcare.com/articles/how-to-help-with-bathing-and-personal-hygiene-top-tips-from-caregivers-212010.htm

My Mother hated the water and she was scared and she was also very modest,so I'd put on my bathing suit and leave Mother's bra and panties on her and I'd get into the shower with her and help her ,then when it was time for her private parts,I'd step out and she'd do whatever.Then I'd rinse her off and get her out.
Idk if this helps.it's just what worked for us.

This can lead to serious health issues, like skin breakdown and infection. Perhaps he needs medication to calm his agitation, something to discuss with the doctor.

Will he accept a flannel wash or a bedbath? Is he easier to do things with at a certain time of day, like just after waking or just before bed? If not, would his doctor help by prescribing a sedative for bedtime to enable you to do what your father needs?
Apologies for not giving better advice. It's a difficult one. My FIL is 88 and chair bound, and was refusing showers initially but now he looks forward to his one a week. It's not enough but at least it's something.