I'm not one to 3bet OOP on a draw normally. It worked out nicely this time, but is this a standard play for you guys who are good at 6max limit? Or is that a donk play more often than not?

PokerStars 2/4 Hold'em (4 handed)

Preflop: Hero is BB with , .
UTG raises, Button calls, 1 fold, Hero 3-bets, UTG calls, Button caps, Hero calls, UTG calls.

Flop: (12.50 SB) , , (3 players)
Hero bets, UTG calls $2 (All-In), Button raises, Hero 3-bets, Button calls $2 (All-In).

Turn: (9.75 BB) (3 players, 2 all-in)

River: (9.75 BB) (3 players, 2 all-in)

Final Pot: 9.75 BB
Main Pot: 7.75 BB, between Hero, UTG and Button. > Pot won by Hero (7.75 BB).
Pot 2: 2 BB, between Hero and Button. > Pot won by Hero (2 BB).

Results in white below:
Hero has As Js (flush, ace high).
UTG has Ad 9d (one pair, nines).
Button has 9c Qc (one pair, nines).
Outcome: Hero wins 9.75 BB.

With their stacks how could you not do that?

I like. I don't play six-handed, but I think AJs is a monster four-handed. Might as well get their money in there now so they don't have a chance to back out later.