I'll start with this... I don't believe in them. So that should put me on your #%#@ list right off the bat.
Had a neck/nerve problem a few years ago that my doctor(s) could not help me with....I surrendered to friends' suggesting to see a chiropractor. Before going I told friends, "My neck has never cracked once in my life".... to which friends replied, "Oh are you in for a surprise... it's going to snap like you won't believe".
Went to the chiropractor and said the same to him, "my neck has never cracked once".... he replied, "Oh are you in for a surprise"... He went to work:
THIS... zip... THAT... nada... OK THEN THIS... silence... "MORE FORCE".... zip-a-roo"... My neck never cracked once. Not even a peep of a crack. When I left the chiropractor he was a dejected and defeated man. My neck problem remained with nary a crack. That was my last, and only, trip to a chiropractor.