Rutger Wilhelm published a book last month on cluttering... https://www.amazon.com/Too-fast-words-discovering-stutter/dp/B08NDVKM3P/
I have cluttering, and the best technique for me is to try to match my rate with my conversation partner or listener.
If you're an SLP, your target should be a lot slower than your conversation partner, since everyone will be modeling your speech, and it's easier to model slower speech.