Re: Plastic cover over pocket diaper?
A lot of babies just reach a point when the standard microfiber insert is not enough to hold their pee. You might try double stuffing them, or using bamboo inserts, or switching diapers entirely. My entire stash was Fuzzibunz when I started, but unfortunately they just didn't work out for us. We mostly use Itti Bitti Tuttos and Goodmamas now.
Putting a cover over the pocket diaper won't fix the underlying problem.