This tactic has a name in Chinese Go terminology called - 粘劫收後, filling (by winning) the ko and get the last play/dame.
It’s under the circumstance where one side can start the ko and has more (valid) ko threats and can fill the last dame. Keep the ko going but don’t actually use ko threats, instead playing “neutral points” as if they are ko threats. If the opponent play the ko, keep playing ko. If the opponent fills dame, you also fill dame (treating dame move like a ko). When you get the last dame, and still have more ko threats (the opponents run out of valid ko threats, but only loss-making threats), the opponent would be forced to pass (or risk losing more and more), and you can finally fill the ko to get extra points.
There are even more extreme cases, where the ko are step-ko, and if one side has much more ko threats, when the opponents run out of (valid) ko threats, they would have to pass several steps, and under the Chinese rule, it would be winning step number more points.