Is There a Limit to How Long You Can Keep Your Lexa Skills Privately?

If you're going to submit something and not use it just for personal use, nothing beats actually using a a hardware device. Is there a way to make like, personal skills that your lexa has that are not public? It's like, associated with your amazon account, like, i think it's in development or something. That's what the skill is marked as. But do you guys know if that leg persists, or is there like, a limit to how long you can keep it, like, running privately? I don't there's a limit, cause i, i definitely have some old ones lingering that i haven't cleared out. Until lamdow starts to charge money