I ran, and am still running pod filters in the UK, where we are used to a little rain, and I have never had any issues. I.e. there is nothing to be worried about on that score. The pod filter detractors often like to back up their arguments with a little embellishment.......
That said, I would not recommend running the bike, whilst stationary, and directing a hosepipe jet at the pod filters just for fun.
Cheers
rev light