does this still work?

It does. For now. Soon, though, they're gonna wipe that system and put in a new one. With the express intention of removing abuse incentives.

Refer a friend fraud is no laughing matter. http://forums.na.leagueoflegends.com/board/showthread.php?t=2088377

http://rewards.na.leagueoflegends.com/terms-and-conditions

Any LoL Player or other individual who attempts or otherwise encourages, directly or indirectly, referrals under multiple identities, and/or uses multiple computers, multiple Internet Protocol or email addresses, so-called “proxy servers,” or any software program to manipulate or create multiple identities/referrals, or uses any other device, method, or artifice to create or encourage, directly or indirectly, false referrals, as determined by Riot Games, will be disqualified from further Program participation and the LoL Player’s Game account may be terminated.

If you think you will be exempt from punishment then, by all means, go right ahead.