I designed an active bug debouncer circuit in 1992 and a version of it is sold in kit form by WB9KZY as the Bug Descratcher Kit III.
For folks who like to build things, another option is my "S-QSK Mini" device, shown at the top of my QRZ page. The total cost is slightly more than the WB9KZY kit, mostly due to shipping charges from two different vendors. The PC board Gerber files are available on the same QRZ page -- or order the board directly from OshPark. I've nothing to sell. Files and instructions are all free. No need to hunt down parts; parts can be ordered with a "one-click" link to Mouser.
A few benefits:
1) Precise, user adjustable debounce time in 1 ms. increments with a simple one-line code change;
2) RCA phono input and output connectors. No wires soldered to the S-QSK Mini board. Just grab RCA cables;
3) No soldered wiring for power. S-QSK Mini is powered exclusively from any USB jack including a close-by PC, iPhone wall cube, or any of the hundreds of +12v to USB powering devices;
4) Full optical input and output isolation to mitigate RFI issues;
5) Output device is an Ixys PLA140, fully balanced above ground potential and will key AC or DC loads. Standard positive or high voltage grid-block keying -- it doesn't matter.
Because of the debounce time flexibility, it does require flashing the code to the microcontroller using free Arduino IDE software. S-QSK Mini construction time should be under 15 minutes, even for those with minimal kit building skill.
Paul, W9AC