How can I convince my mother that using wipes isn't a good replacement for a proper bath?

A fellow caregiver asked...

My 80 year old mother refuses to shower or take a bath. She insists that using "bathing" wipes from a package is doing the trick. She is very unstead and walks with a walker, but we just renovated her bathroom the shower is new and wide with a nice shower seat and grab bars and she still refuses to use it. She makes excuse after excuse. Her hair gets so dirty and rather than let me help her in the shower she will ask my Dad to drive her to the beauty shop so they can wash it. But she herself needs to be washed. She doesn't "smell" per se, but I know she is not able to get herself as clean as she should as she wears diapers and often soils them.

She has only let me help her get a shower once and once she came out she said she felt so much better, but that was almost a year ago. Since then she's only been using the wipes. She also smokes a lot so the smoke is in her hair and on her skin and I feel like it should be washed off regularly - at least once a week.

Everytime I bring it up to her she gets defensive and tells me that she doesn't want to shower. She says the wipes are doing a fine job. She gets angry and then shuts down and wont talk about it at all. My Dad is frustrated also because he said she gets an attitude with him also if he suggests she shower - so he just stops asking.

I have offered to pay a healthcare professional to come in to help with bathing in case it was a matter of her just not wanting me to do it, but she is refusing that also. My father is older than she is and he showers every day.

I just don't know what to do to get her to bathe. I don't feel like the wipes are an appropriate method of bathing. If she were completely bedridden then she would have to resort to a sponge bath in bed, but I understand that would involve washclothes and rinsing with clean water. But, she's only using the wipes and refusing to consider any other option.

Any suggestions would be much appreciated. She's lucid and that isn't the problem, so I thought if there was some sort of documentation that said "wipes" weren't an acceptable way of bathing she might be more receptive. But for now it just seems like she thinks I'm being completely unreasonable for asking her to shower.