What dirt is there going to be in a 91-year-old's cupboards in a month for heaven's sake. Or a much younger person's for that matter. Am presuming food cupboards here, unless you habitually put jars of leaky jam on their sides or holey flour bags, in which case that's different, what's wrong with an annual go through of the cupboards to get rid of/use up old half empty jars/packets etc, ok maybe twice a year if you are 'slovenly'. As long as things are clean and you are happy with that, that should be enough. Keep up with it on a day to day basis, vacuum when it needs it, keep the loo clean and keep on top of the washing up and kitchen surfaces, and be a bit careful you use the old stuff in your cupboard first and in general you probably only need to do deep cleaning occasionally when needed
Oddly I was watching one of those programmes last night with someone with a cluttered house in need of deep cleaning was paired with someone who spent hours cleaning and bleaching their house. One of the 'clean ' people had started cleaning after her son died so she could feel in control of her life, if she felt bad she would clean, the other was lonely as her husband worked away, and cleaned to fill her time. The first lady decided to seek help for her obsession, the second lady started volunteering to clean friends' houses, and considered getting a job. Often those on the other end of the spectrum too, have had a trauma, a death, or other such loss leading to difficulties. Both deserve help. If you are somewhere in the middle and your house is safe and you are happy, all is well. I thought last night that the lady who was bored could maybe do gardening or volunteer for a good cause if she didn't want a job, rather than clean unnecessarily, or even do some fun study or join a club but everyone is different. I'd love her to come and clean my house though lol
If Aunt is happy doing what she does, fine, but she'd not be happy if you started telling her she was boring and should do something interesting