To be said in response to a question about how things are going at work or on a project when things are going well. When term is coupled with a hang lose hand sign it means things are going exceptionally well!
"like dicks on a snake" would mean the opposite, things are not going well.
"How are you and Tommy coming along running that copper tubing on the roof?" "Like snakes on a dick, boss"
"How's your science project coming along, little Willie?" "like snakes on a dick, dad"