Transitioning a friend/LO to just a friend

Hi folks. I befriended someone last year because I had a distant crush on him. As we became better friends, my distant crush turned into limerence. We've been developing a real friendship this whole time, but my feelings for him haven't faded. Months ago I told him via text I had a crush on him and he gently rejected me, saying he really liked being my friend.

I don't want to have to wade through limerence for another 1-2 years before I shake it, and I don't want to go NC because he's a really good friend at this point. Even with the initial rejection, my limerence has survived on this shred of hope: that even though my friend is asexual and demiromantic (in addition to not being interested), he will eventually return my feelings (as a demisexual myself, I know that for some ace-spec people attraction can take years to develop).

I am considering asking him to reject me again, harshly, in person. Is this a nuclear option? Has anyone here had success with a harsh in-person rejection shaking them out of their daydream?