Yes, a Jain layperson can brush three times a day if needed for cleanliness and health.

From the Jain point of view, the main care is to follow:

• Ahimsa: do it gently and avoid unnecessary harm
• Aparigraha: do not waste toothpaste, water, or resources
• Self-discipline: keep the practice moderate and purposeful

There is no general Jain rule that forbids brushing three times a day. For monks and nuns, the discipline is much stricter, but for householders, daily hygiene is acceptable.

If someone is following a special vow, fasting, or a strict religious observance, they may choose a more restrained practice according to their tradition.