I am normally the advocator of the non three street bluff, though I (thought) I had pulled it off in this case. I think this is a better move out of position then in. Here's an example:

PokerStars 3/6 Hold'em (9 handed)

Preflop: Hero is UTG with , . CO posts a blind of $3.
Hero raises, UTG+1 3-bets, 5 folds, SB calls, 1 fold, Hero caps, UTG+1 calls, SB calls.

Standard

Flop: (14 SB) , , (3 players)
SB checks, Hero bets, UTG+1 raises, SB folds, Hero 3-bets, UTG+1 calls.

Standard, almost thought about checking it through to let UTG+1 bet and try and get SB to call a bet and then my checkraise, but decided might as well give UTG+1 a chance to fold his 10's JJ or AK. When he raises me I've got so many outs I reraise and take control.

Turn: (10 BB) (2 players)
Hero bets, UTG+1 calls.

Standard after a flop 3 bet.

River: (12 BB) (2 players)
Hero bets, UTG+1 calls.

Now this is tough. He's called down, I figure he probably has a pair. But with the 12 BB pot already I think I have to bet here, on the offchance he has AK or maybe and underpair he was looking to set up and folds.

Final Pot: 14 BB

Results below:
Hero has Kh Ah (one pair, eights).
UTG+1 has Ks Ad (one pair, eights).
Outcome: Hero wins 7 BB. UTG+1 wins 7 BB.

DAMNIT!!! Played to perfection and I still get nothing out of it. Hella weak.

You played your hand fine he played his like a donk, thats pretty much all there is to that. Him callin that river is pretty -EV it seems to me. ALthough, i think i mightve checked the river, figuring if hes got JJ or 99 hes gonna make the slutty river call, since he called the turn, and if hes got AK he'd let it go, i would THINK anyways... I dont think youll find very many 3/6 players that will call the turn with a pair and muck the river to the apparent value bet when no scare card comes, and your also not gonna find too many 3/6 players that'll call that river with AK, unless the game is short handed. I think your river bet is going to be -EV, more often than not, because any hand that you beat, with the rare exception of a chop, is usually not going to call you, and most weak made hands that he decided to call the turn with, he is not going to muck on the river when a blank hits.