The local mikveh where I grew up would send out bedikat chametz kits every year as a fundraiser. Sometimes, we day school students would be drafted into assembling them: feather, spoon, candle, all into an envelope. This was so natural to me that it never occurred to me that it was incongruous for the mikvah’s fundraiser to be Pesach-specific. While I’m confident that this really was just a cute fundraiser idea that endured for years, there is actually a deep connection between niddah practice and the search for chametz. After all, they both involve careful bedikot.
Thank you for this!