Deleting Dropped Pins in My Places in Apple Maps

I've seen a number of questions like this with no resolution. I'm posting this because Apple Support was able to solve this for me, so I thought I'd pass it along. Many thanks to Apple's second level support for the perseverance they showed in working this out.

"My Places" was propagated from an older version of Apple Maps, and trying to delete a dropped pin from "My Places" directly does not work. Instead, the following procedure worked for me (I hope I transcribed it correctly).

For those pins that cannot be deleted directly,

1. Add the dropped pins in "My Places" to "Favourites".
2. Go into "Favourites", scroll down to the bottom and hit "Edit".
3. Each dropped pin will how have a tick-box open on the left. Click in the tick-box for the dropped pin to select it.
4. At the bottom right, "Delete" will light up. Click on "Delete".
5. When all the dropped pins in "My Places" have been deleted, "My Places" will also disappear.
6. An anomaly during this procedure: we had to try to delete the very last dropped pin at least twice to make it work, perhaps thrice. No idea why, but when it finally worked, I was just as happy not to raise any questions.
7. This was done on an iPhone 13 mini running iOS 16.6(20G75).