I wouldn't submerge a PTW, nor any gun with electronic controls (Trigger Master, whatever).
I wouldn't be too worried about rusting steel parts on any AEG, most have little more than the occasional screw being steel at best. The motor would survive fine, but it's life expectancy would be reduced as the arc damage from the brushes on the comm would be pretty good with water as an insulator. DC does not flow very well through water.
The switch might not like the water very much either.
Age verifier Northern Alberta
Democracy is two wolves and a sheep discussing what's for dinner.
Freedom is the wolves limping away while the sheep reloads.
Never confuse freedom with democracy.