>>42235085
>Best spanking age?
I lean toward that higher bracket.
Older foals create more elaborate schemes for mischief and fool proof plans to stay out of trouble and unspanked.
When those evil schemes come crashing down that's when they are the cutest & funniest. They get more embarrassed too.

>>42235933
Ask Cookie C.
She's kept a Mommy diary since Rarity was born. She's recorded every spanking they ever got, what naughtiness brought it upon them and what tool was used for the whacking.

She'll show it to you, and discuss it in enthusiastic detail
She'll do this in front of her two fillies.
In public.
With other ponies and strangers listening.
You won't have to ask her to repeat herself, Cookie speaks in a very loud voice.