How to disable natural scrolling on Mac OS X (El Captain) with command line?

I would like to use natural scroll with touchpad and normal scroll when I am using a normal USB mouse. I don't want to go to the preferences dialog to change the settings every time I need the switch. Thus I need a command line tool to help me with that.

Here is what I put in my ~/.bashrc:

alias scr-natural='defaults write NSGlobalDomain com.apple.swipescrolldirection -bool TRUE && killall cfprefsd'
alias scr-normal='defaults write NSGlobalDomain com.apple.swipescrolldirection -bool FALSE && killall cfprefsd'

After I run scr-normal and then

defaults read NSGlobalDomain com.apple.swipescrolldirection

I can see the value is 0. However the behavior is still the natural scrolling.

I searched a lot of places and it says the preference dialog will set the new value and force system to reload the ~/Library/Preferences/.GlobalPreferences.plist file. I couldn't find anyway to force system to reload that file through command line and I get stuck over there.

Can anyone help out?

Okay, not a direct answer to this question, but a answer to solve my real problem:

Go to http://pilotmoon.com/scrollreverser/ and download the software, it can tweak the system so that I can use natural scroll for trackpad and normal scroll for my external USB mouse