Possible Clues:

• Around the neck it's certain not to work
• Incentive to admit drug is not working
• If you're not working, you'll get it in the neck for certain
• If one is not working one gets it in the neck for certain
• Enjoyment of free time
• Round the neck and at the end of 24 across this just won't work
• Is to get it in the neck certain not to work?
• Convenience outside one's primitive shelter
• Free time as for resting or play
• Strings of flowers, another and the rest