There's no need to actually wipe your prodinfo any more, and it's not worth the risk of recommending it, at least on sysnand. The number of permanently damaged Switches I see posted about because people lost their prodinfo backup makes me sad (and worse is people unknowingly buying said Switches). You can use Atmosphere's on-the-fly prodinfo blanking, its new DNS redirection, and 90dns - any of them should do the job, but no harm in combining all three.
He mentioned EmuNand, I would definitely not recommend doing it on SysNand at all.