Acetylcholine is not used commercially because:
Long duration of action
Costly
rapidly destroyed in the body
Crosses blood brain barrier
Ref:KD Tripathi pharmacology 7th edition (page.no: 99) ACh is hydrolyzed by the enzyme cholinesterase and choline is recycled. A specific (Acetylcholinesterase-AChE or true cholinesterase) and a nonspecific (Butyrylcholinesterase-BuChE or pseudocholinesterase) type of enzyme occur in the body. So Ach is rapidly destroyed in the body
Autonomic nervous system