I just saw and commented on a thread "Do You Think Diapers Look Good On You?" I think wearing just briefs alone I can accept as OK. Wearing lined plastic pants over them looks silly to me.
I took to wearing the lined pants as an antidote for leaks in bed and while sitting, especially while driving my car. I first saw them offered by Babykins/Kins and knew this would be a practical solution. I bought terry-lined polyester/vinyl pants and never once had a leak from my disposables go beyond the over-pant. Those were expensive and after a matter of months the plastic pant got brittle and cracked.
I cut off the plastic pant, keeping the terry lining and bought some plastic pants from Gary. They will work nicely, but they're cut big and look pretty damn foolish. However, I'm OK with that, I guess. I know this is secure. I know this is practical. And I know this is about as cost-effective as I can get. From a performance point of view, this is the good stuff, even if the downside is looking foolish. (The plastic pant I got from Gary are the milky white; they're thick plastic, but will be durable and a good value, I think.)