Forcing Cum Swallow During Self-bondage with Bondage Techniques

Hi all, I’m new here and curious if anyone has tips on how to make yourself swallow your cum while self-bondage is in place. I always enjoy it at the start, but once I climax, my willingness drops. It would be nice to find a method where binding ensures that when I do come, swallowing becomes inevitable. One idea of mine involves using one of those milking devices that somehow captures and directs the milked cum into my mouth. The downside is these machines are incredibly pricey. Any thoughts? Thanks!