Final answer:
To remove dirt, oils, and products residue from the barrel of a thermal iron, use a dampened towel with a soapy solution containing a few drops of: b) Shampoo.
Step-by-step explanation:
Shampoo is the best option to remove dirt, oils, and product residue from the barrel of a thermal iron. Shampoo contains chemicals called surfactants that are designed to dissolve oils and grease. When you dampen a towel with a soapy solution containing a few drops of shampoo, the surfactants in the shampoo will interact with the dirt, oils, and product residue, helping to lift them off the iron's barrel.
For example, sodium lauryl sulfate and sodium laureth sulfate are common surfactants found in shampoo. These surfactants have hydrophobic tails that are attracted to oils and grease, and hydrophilic heads that are attracted to water. When you apply shampoo to the iron's barrel and wipe it with a dampened towel, the surfactants in the shampoo will surround and trap the dirt, oils, and product residue, allowing them to be rinsed away with water.
Conditioner, hairspray, and gel are not as effective as shampoo for cleaning a thermal iron. Conditioner is designed to soften and detangle hair, not to remove dirt or oil. Hairspray and gel are styling products that contain ingredients that may leave residue on the iron's barrel. Therefore, to achieve the best results, it is recommended to use shampoo with surfactants to clean the barrel of a thermal iron. The correct answer is b) Shampoo.