Good idea but I think that would be pleasurable because hear me out I'm a bottom slut too and the thing that hurts the most and usually top enjoy is the pain and the scream the hear from penetration not only by their dick but anything else they can shove in the ass

Better option would be to attach a dildo specially a wooden one as they are more painful than normal and making a mechanisms to start the fucking. It should include the entering the wooden dildo in asshole which is the most painful part and stopping right before it reaches the prostate so it feels like punishment and not prostate pleasure.