Blarney Stone is great but I feel like it’s more about thinking of the right things to say or knowing the right things to say on a soul level rather than the mechanics of speech
But anyone feel free to chime in on that I could be wrong
So there isn’t one directly for this that I know of but I will suggest all the fields that I can think of that could potentially help with speech in general.
The key to babel (paid, gumroad) - this is a brain field primarily. But with the rewiring of certain parts of the brain perhaps your motor functioning could improve.
The divine voice (paid, nft)
The voice of reason (paid)
Is this an injury? Or always you had this?
If it’s an injury:
Fat to stem cells (free)
Stem cells and scar tissue (free)
Smart stem cells (paid)
Plasma flaunt (paid)
Max heal (paid, nft)
If it’s always been there:
Blueprint of life (paid)
Flower of life (free)
Negentropic Mewing (patreon 4.50 tier)
Since you think it might be a muscular issue:
Muscles hungry for fat (free) + blueprint of life or muscles hungry for fat + flower of life
Or
Fat to stem cells + blueprint of life or flower of life
Smart stem cells + blueprint/flower
Could also use the dna repair system (free)