Not usually, but I've played it in a few games just messing around; in fact, I made a video about this opening before:
All things Grob

Not usually, but I've played it in a few games just messing around; in fact, I made a video about this opening before:
Yes sir, I have watched this video. I also intend to dive further into it. It was quite helpful and I enjoyed your teaching style. If I have questions about the material in the video, can I ask them here?
In 1989 between April and July I played the Grob as white, 1 g4, and the Macho Grob as black, 1 e4 g5 or 1 d4 h6 2 e4 g5, in every game. The single exception was against an IM who began 1 Nf3 h6 2 b3 !? at which point I answered 2... d5 3 Bb2 Nf6 and went into an ordinary London System. In that span of time I played more than 50 rated games, and at the end my Elo (both USCF and FIDE) was higher than when I started! Does that mean the Grob is a good opening? No! But many players don't react calmly when faced with a rare and provocative opening.
My opinion is that the Grob with white ( 1 g4 ) is very unpleasant but probably doesn't lose by force. The Macho Grob with black ( 1 e4 g5 ) is unbearably unpleasant and probably does lose by force. After I lost with the Macho Grob versus GM Patrick Wolff, he had this to say:
"I'm convinced that the best way to meet the Macho Grob is for white to develop, castle kingside, and play f4." --GM Patrick Wolff
The GM hit the nail on the head. The (Macho) Grob pawn moves on the kingside "threaten" exactly nothing, so castling kingside is perfectly safe. And the f-pawn break harmonizes much more nicely with kingside castling than the more commonly played h-pawn break.
My two cents. By the way, I have a 100% score when facing the (Macho) Grob. It's much nicer to be sitting on the other side.

1.g4 is the worst first move by far, out of twenty. Is that enough?
Oh, I understand completely. Probably the best thing that I can say in the Grobs defense is that it at least provides more counter play than resignation.
Although, it's not the 1.g4 part that actually bothers me about playing it. It's the "where do we go from here?" Part to establish a reasonable position ( or at least a defendable one) to weather the storm through the middle game once the potential tricks and traps exhaust themselves.
If white via the Grob can get to a playable endgame it's just as viable as any other openings in theory.

f3 is just as bad as g4, right?
No. To my understanding, the computers view 1.f3 as a better move than 1.g4 if even not by much.

I dabble with the Grob occasionally; more out of admiration for the games of the late IM Mike Basman than because I think it good. My tips: 1) Don't go near it without a copy of "U Cannot Be Serious" [Welling and Basman] or at least the older "The Killer Grob" [Basman]; and 2) Unless you are Basman reincarnate, use it as an occasional surprise weapon not your main opening; and 3) Don't touch it as Black...although it might be playable against 1. c4; and 4) Be prepared for howls of derision. My question to others: I've not invested in a copy of "Basman's Folly" [Lakdawala and Hansen] - can anyone who owns a copy of both this and the Basman books tell me whether or not it's worth getting?

Grob might be a good psychological weapon against certain opponents: like people who will be offended and annoyed that you had the gall to play it against them, and who may respond poorly or use up a lot of time.
Me, I'm like Bobby Fischer (well, except for that whole talent thing). I believe in good moves

f3 is just as bad as g4, right?
No. To my understanding, the computers view 1.f3 as a better move than 1.g4 if even not by much.
1.f3 isn't even half as bad.
I'm a weirdo. I like to study openings that I don't necessarily play. I play openings that you are not necessarily supposed to play in the opinion of the masses.
Anyway, recently I have begun studying the Grob opening. Does anyone play it ?