This is the easiest solution, if you have working batteries or NVRAM in the game. The only thing that stinks is that on -17 games, the score increases sooooo slowly to come back around to "0". On -35 games, it's not that bad.

I have tried them when repairing a game. They work but using them assumes that you have an original board in the game (or a newer Weebly board that uses original rom sockets) and the ability to burn those roms correctly AND properly jumping the MPU AND that the DIPS on the MPU are working properly. It's a lot to take in for people that are just getting their feet wet, not well versed in MPU work.

Absolute pain in the ass to add switches on a machine where they were not meant to be. Easiest solution is to press the coin door button and set replay low. Takes 90 seconds. Earn a replay with the second and third scores, nothing changes. Points 2-4 above hold true for this solution and it's also faster. With most games I work on the customer doesn't even want the knocker to go off at all and they ask me to disconnect it or, it's already disconnected.

I have done it more than 50 times both ways. I’ve been fixing games for 20 years. Trust me, changing Replay is easier.