As of version 7 of the Containers extension, ctrl+shift+1-9 works without any further add-on. From the release notes:
Set shortcuts in the add-on preferences panel:
Ctrl + Shift + {Num}
Which containers correspond to which number can be configured in the add-on preferences.
As mentioned in other answers, ctrl+., tab also works.
On MacOS it's cmd+shift+{num}