As the article says :P Why is everybody suddenly changing swappiness, I did it too. I didn't really notice any change in the speed.
Here is how. Login as root. and run the command sysctl -w vm.swappiness=10
Or you can edit the sysctl.conf file in the /etc folder. I did that only to find out that sysctl.conf file does not exist in Slackware. Created my own and seems to work.