Yeah, it's a good idea. Don't be afraid to experiments, but yes, rewarding a bad ending is already used in many games already, so it's a good idea.
I never play Corpse Party, but there are plenty of other good examples of such games...
The most infamous "rewarding a bad ending" is School Days. In fact, the bad endings over-shadow all other good and normal endings!!! Lots of people play to get the bad endings... No, the game itself is famous BECAUSE OF the bad endings. If you want to watch the bad endings, there are plenty in YouTube.
In Lighting Warrior Raidy 1 and 2, a hybrid RPG-VN (with main female protagonist), most of the sex scenes could only be unlocked if Raidy lost (meaning bad endings, better save beforehand). Actually, in lots of H-game with female protagonist (and some kind of mechanism where you could lose), there will be a special H-scene if the protagonist lost (bad ending). In some of those games, lose is something difficult to do that you have to deliberately kill yourself to achieve bad endings.
In 999, ...
you have to get all the bad endings before getting the true/good one (actually all minus one since I accidentally skipped one of the bad ending and now it's impossible to get it without resetting the game data).
Not bad endings, but in Private Nurse, ...
You could unlock a new epilogues (or called as "diary" in this game) only if you get non-canon ending (end up with other two other girls, not the main one whose have the longest story, almost triple the amount of other girls).
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"Double the princesses, quadruple the fun!" - Haken Browning (SRW-OG Endless Frontier)
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