Selective shoving worked pretty well for the Halloween SnG promo, but they were 9-player tables. As such I’m not entirely surprised by the results @Max17903 had. Your last point in that paragraph is pretty key: there is always another one starting if you lost. So you get your points for the LB and move on to the next one. You are definitely gambling… but… if you have a bigger picture you are working on, frequent shoving is an efficient albeit risky method.
This is essentially what you do in the 500 B+R Bankroll builder or the other Rebuy tournaments. See the thread below.
Also, I would suggest to @Max17903, if you want to try this in an MTT without rebuys, the 2.5K Ruby tournaments are quite shove-happy early on. Of course, the Freerolls would be less expensive and a much, much more difficult task as they frequently get 200 or so entrants.