If you have a ton of parent directories and you want to script this instead of doing it by hand:

icacls "c:\parentDirectory\*" /q /c /t /reset

Shoud have the same effect as clicking the Replace all child object permissions with inheritable permissions from this object checkbox.

Un jour, peut-être. Pour Bytes ! ;)

Marrant, je parlais justement de ladite limitation à un client aujourd'hui !