We were at Universal last Thursday and Sunday. Thursday, the remmants of IDA kept Orlando at the mid-fifties and windy. Amazing, no wait for Popeye at all, nor Dudley. We didn't go. Sunday, not a cloud in the sky and 81, still no wait for either. We did both, several times.
Dudley will get you wet, but mostly your top and front and the front seats are wetter. Ponchoes will moderately help.
Popeye is a fully wet ride. Water comes from all directions, above, the side and the rear. Ponchos are no help here. It is also one of my favorites rides at the parks. Much better than Kali River Rapids at Animal Kingdom, much, much, better!
Mind you, I like getting wet, so my view is that ponchoes are for wimps. I'm the guy who gets off the ride 90% wet and then jumps around the fountains in and around the cartoon area to complete my soaking. However, knowing that wet shoes and socks can lead to blisters, I always have a change handy.
Dolby1000