git checkout ( then press Tab twice), shows a list of branches including already deleted ones.
Most of them are not exist in the list from git branch -a. They can not be removed by git branch -D trash_branch
How could I clean up the list remembered by git chechout?
Your issue is that the remote status it not reflected on the local git clone. You can prune the remotely deleted branches with:
git fetch -p
Then continue by deleting the local ones as you already described.
git branch -D <branch name>
To see the current status of branches compared to the remote, use this useful command: (thanks Erik Schierboom)
git for-each-ref --format '%(refname:short) %(upstream:track)' refs/heads