Yeah, definitely tough. Considering that you don't want to be wet, mineon resists bludgeoning and piercing, and oscillator resists piercing and water (and electric)...
1. Slingshot, and if you don't get a critical, flee and try again. That should be 30 off oscillator, 30 off lasher, and 8 off mineon.
2. Dynamite the mineon, which should finish it off.
3. If you are not dizzy, hammer the oscillator (trying for a critical)...otherwise dynamite to finish it off.
4. If anything other than the Lasher is still alive, use slingshot. Otherwise Pistols on Lasher.
5. Finish off Lasher with your favorite weapon if needed.