Modifiers matching shampoo:

• mild,
• animal,
• delicate,
• gentle,
• natural,
• special,
• irritating,
• alkaline,

Simple categories matching gentle:

• sedative,
• modality,
• fabric,
• ingredient,
• animal,
• cleanser,
• token,
• therapy,
• herb,
• hill,
• sound,
• spice,
• creature,
• shampoo,
• grain,