Thanks for the replies. As dumb as this may sound, I actually have a Splendide in my 5th wheel that I've never used. I actually bought it for a boat about 15 years ago! LOL
I honestly don't remember if it's vented or not, or if a non-vented model can be changed to vented. Bought it off eBay and never even tried it (long story). Maybe it's time to give it a try.