I too am old
and still do a bit of detailing as I love the end result.
I can't use a machine polisher anymore my arms an Arthritis prevent me.
The quickest and easiest wash I found is to thoroughly spray the car all over using a pump spray bottle filled with a mix of Optimum no rinse.
Using a bucket of water with the same solution and microfibre cloths, simply wipe the car all over with well wetted cloths, changing the sides frequently as you go then dry with a MF cloth or drying towel.
On the Jazz the whole wash takes 20 mins or 30 at leisure.
If you wish, use a spray wax or detail spray for a more glossy finish and to add some protection.
This method is particularly suited to anyone who can't get running water to the car and it keeps swirl marks to a minimum.
Harry