Hmm, okay can't get 'em out by hand. Well, haven't tried this on mine so can't say definitely nor have I had water in mine so until that happens I'm kinda shooting from the hip on this particular gauge setup but despite that Ill run my mouth a little, LOL.
These I'm sure are made by Faria so maybe you can get info from their site. Must be a "waterproof" version.
So often I see gauges that don't work have moisture or moisture stains in them, mostly the ones owner asks for replacement are water damaged or he suffers looking at failed gauge in his face. Sad actually, but common.
I'd be tempted to aerate by making holes, one in bottom too so water can run out. Moisture is one of our big enemies.
I'm assuming now, water entered from front side lens gasket and not backside moisture but not that it matters a whole bunch.
Submerge in dry rice trick? I still think fan blowing through holes in rear is good approach but no holes for this.
Owner Common Sense Self Assessment: Does making holes compromise gauge durability or improve? (ie:How did water enter, front or rear. What's to lose or compromise, pluses or minuses?)
Also reconsider advice provided above, "leave ski in warm sun"?
Dunno what else to say except hope for good luck with your decision and consult Faria web site maybe (Or maybe Teleflex gauges, but I'm pretty sure it's Faria in this case.
I'm curious about what you decide so I can learn something.