Villain: pretty spewy and seems to show a lot of mistimed aggression. Seems to never be able to resist betting when checked to (e.g. will always bet missed draws, 67 on a A37K3 board even with no chance of winning the pot) but hasn't really raised on any street as far as I remember. I haven't seen him 3 bet once in the last hour he has been at the table. Recently got felted, lobbied for about half an hour and then bought back in for his last $364 but then has been winning a bit since then and doesn't seem to be tilted at the moment, although he is probably drunk.

I have QQ UTG and raise, Villain 3 bets UTG+1, BB calls, I cap, Villain calls, BB calls.

Flop KJ3r, I bet, Villain raises, BB folds, I call.
Turn J, I check call.
River 5, I check call.

I'd call the preflop 3 bet. I think it's likely that the big blind shouldn't 4 bet anything here, which makes his range quite strong and the position of the preflop 3 bettor is such that he should have a very strong range too. I have lots of hands in my range that cannot 4 bet like AJo, 77, KQ, and more which will only call the 3 bet. If I 4 bet it's probably only correct to do so with a very narrow range like QQ+, AKs. This is why I call the preflop 3 bet with my whole range and see a flop.

Then on the flop I'd check call for one and fold for two.

As played preflop the rest is pretty standard. Hope to see AQs or an overplayed TT. Expect to lose the majority of the time.

Villain is described as spewy. We have no info on BB but if he is also too loose pre then 4b pre is warranted.

So now bluffing non showdownable hands on the river = spewy? I disagree and I think it's plain old good poker. All we have for a read is this:

This is nowhere near what I would describe as spewy poker.

Agreed. Against spewmonsters, just jam. Give them a chance to spew more.

I agree w 4bet, may 4bet as low as 99,AQs against described opponent. He's stuck and jamming.

Is he in the sobering up phase? People sobering up psychologically want to play better poker and not make all the mistakes they made while drunk.

How long was it since his last drink?

After the flop raise, you only beat a bluff so calculate 2.5 bb to win 10.25 bb (12.5 sb pre + 4 sb flop = 8.25bb + 2 implied bb turn/river).

The 4bet pre makes the bluff less likely, but it's a judgement call.