I suspect the answer is, you can't.
But for context. My Dad (66) lives alone in a small 3 bed house, has been there for over 40 years. He is sadly widowed as my Mum died over 3 years ago. I (32F) live 100 miles away and am an only child, I plan to move closer at some point but jobs/partner/mortgage obviously make that complicated.
I love my Dad but hate actually going home. He is trying bless him, keeping on top of basic tasks like changing sheets, washing up and food shop. They had a very traditional marriage so all this is very new to him.
However, he has ALWAYS been an absolute slob, leaving litter in his van, table crammed full of paperwork and spam post coathangers of clothes everywhere because his wardrobe is crammed full of old clothes. Everywhere is just a bit grubby from where he touches surfaces after work. My Mum found it so hard but tried to contain his mess and semi hoarding.
He keeps saying things like 'I need to slow down…I want to get this job done at home… I could do with fixing this'
He still works full time, self employed, not because he has to but because he enjoys it and frankly struggles to have a purpose outside work, he never says no to work.He worked 6/7 days a week growing up and that's all he has known. But it means he's too tired or overcommits himself to do anything at home. He is mortgage free with a very good pension so all this is just extra.
I have broached the subject of a cleaner a few times and he says no he'll manage but I think a deep clean every so often would help just to keep it manageable. I think it's a pride thing.
I know as a good daughter I should help but I have my own busy life, mortgage etc. When Mum first died I was there a lot, spending hours cleaning and prepping meals and coming back a few weeks later to see the house in disarray again.
He had a health scare recently and I'm hoping this would make him think about the future more and what would make his life easier but nope.