To get rid of the dot-underscore files, the most efficient way is using find from the Unix side of things:
find . -name '._*' -exec ls {} \;
Once you’ve verified that you’re only looking at files you want to delete, kill them with:
find . -name '._*' -exec rm -v {} \;
And if you have .DS_Store files around that you need to zap as well, then you’d just do:
find . -name '.DS_Store' -exec rm -v {} \;
Other way to delete dot files:
dot_clean <filepath>
Delete ._files on Linux or PC:
find . -type f -name '._*' -delete
Hidden Files
Show hidden files on finder:
defaults write com.apple.Finder AppleShowAllFiles true
Make a folder hidden:
chflags hidden <filepath>>
Note: you can drag the folder into terminal for its filepath
Make a folder unhidden:
chflags nohidden <filepath>
Restart Finder:
killall Finder
Delete files with certain extensions:
rm -rf ./*.tmp