I haven't tried it nearly enough to have any significant stats at 50NL. I know I was limp/calling profitably at 25NL and below... I don't do it anymore because people aren't limping or stacking off lightly nearly as much.
But I think there is a benefit of people putting you on exactly what you have. At 50NL I'm not sure enough people are paying attention, but if you happen to know your opponents, I think you can limp/call and c/r on a bluff. I know I c-bet a limp/caller from EP 90% of the time, so if he would realize that, he'd c/r me on a bluff a fair amount and make moniez.

Folding pp's < 55 in EP is definitely the failsafe option. No need to get tricky, especially at the donk stakes.