[sm0ke]

It would be faster if you were fast enough to drop the bomb and arrow it before their recall went off. Chances are, without a nice macro to do all that for you, you aren't gonna do it in time.
I suggest you scribe like 5 firefield scrolls and test it with another player. If they invis and cast recall immediately after, you can land a firefield scroll on their tile (which hits them) if you cast the firefield within ~.5 seconds. It's a pretty neat thing, has a lot of potential to counter invis potions, but sm0ke has sand in his trap and can't see past his own skull.

Done insulting me yet? This is from an earlier post that you refused to reread apparently you missed it.

I said even if they were implanted there's nothing stopping them from moving from the direction of the firefield and then using the potion so this won't do anything. All this would do is give you a chance to guess where this person is invis on tiles which isn't an accurate fix.