Hi,
If the cheat doesn't work, then you're doing something wrong.
Try typing it, instead of copy-pasting or clear game cache and try again.
As for the "session" duration, you clearly didn't read the wiki, but ok, illiteracy is a thing I cannot overcome by myself, so let me paste it here so you can try again (focus on 2nd sentence after the first '.', starting with "Session-only"):
Hope this helps,
Cheers