I don't think I would. If it were a feature that came with the helmet as kind of an added bonus (safety, performance, other features I like and want) then maybe. To be honest though, even though it is super hot out (and even in traffic) I have never really sweat so much into my helmet that I needed to wash the pads. I wouldn't mind trying it though to see if it makes a big difference. I guess it could be a game changer that no one really knows about because they aren't that common.
Keep the rubber side down!