Possible Clues:

• A sprayer
• When one's canned, a little squirt can produce graffiti
• That little squirt may put an end to 30 across
• Let us spray with the loose R.A.
• Pressurised spray can
• Fine spray (from can)
• 'Ssss' maker
• Loos are dreadful: air-freshener possibly required
• Container with device for releasing contents as fine spray
• O, so real on the blower!