Walmart offers the A/C Pro 10-oz. Vent & Duct Cleaner Vent & Duct Cleaner (pictured) for $7.20. This $5 mail-in rebate drops it to $2.20. Opt for in-store pickup to dodge the $5.99 shipping charge. That's a $5 savings and the best deal we could find. This canned spray cleaner can be used in cars or at home helps prevent odors.

Also available is the A/C Pro Professional Formula Refrigerant for $34.38. This $10 mail-in rebate drops it to $24.38. That's the lowest price we could find by $8. It refills your car's A/C coolant.