the OMM works for anyone, your list of chores and admin is just so much smaller without kids. (at least mine was).
Without kids, I didn't need to use to spend more than one evening a week cleaning, ironing etc.., and maybe another one to do admin. My weekends were always all mine.
TOMM just organises your week by doing a little clean every day of the week, like 20 or 30mn kitchen on Monday, 30mn bedrooms on Tuesday etc.. and using your Friday (or whatever day) doing a deeper 30 mn in a room in turn (including garage, then deeper kitchen the following week, then decluttering your wardrobe following week)
Just a method to stop wasting too much time with housework, but having a house always tidy and visitor-ready and having all your weekends off.
It's very simple and obvious, but her guides helped a lot of people to get more organised and efficient with housekeeping.