Information :
You can use Heal/Clarity every X seconds, where X the cooldown
of Tahms Devour spell is.
So you get clarity every 7 seconds at level 13+.
The exploit is in-game
HowTo
Step 1: Put Any Summoner Spell on D, Put HEAL OR CLARITY on F (AS TAHM!)
Step 2: When Tahm eats you, spam LEFT CLICK on the map.
Step 3: Profit.
Proof: (Video Recorded: 10-07-2015 / 20:23)
https://www.youtube.com/watch?v=TXtfjelAF3M