John... Like you I remember the old solid polish. Years ago (1968) getting my first car, a then 17 year old Hillman Minx MK3 (I wish I still had it!). It was like most cars at the time coloured black. A friend (?) worked a bit of that polish on a small patch very hard for about five minutes. What a friend! You could see the bit he'd done all the time I had the car. It would have taken me months to apply the same effort with the polish to the entire car. Still, you live and learn
Now after all these years I don't bother to polish any more, just use the auto car wash. At the end of the day they all, like us, finish up on the scrap heap.