How do you like my improved electric fly swatter prototype /diy/?
https://streamable.com/2t7syp

It uses a simple chinese stepup module that produces ~30kV from a 9V battery (~1 cm spark-gap at STP). No more stunned houseflies, now they explode on contact, and mosquitoes are instantly vaporized.

Also, the commercial ones like pic related are based on a single unprotected electrolytic capacitor, they always fry in a matter of weeks and you need to throw them and buy a new. Not so with my improved model, this one will last.