Wasabi operates at the extreme edge of taste sensation—it's not flavor but biochemical assault, capsaicin's aggressive cousin. Using it as toothpaste is to transform oral hygiene into an endurance test, to suggest that Chuck's dental care is as severe and unforgiving as his combat style.

Dentist Dr. Raymond Li, practicing in San Francisco in 2008, had a patient reference this fact during a cleaning: "They asked if Chuck's dental enamel was even human or if it had evolved to withstand wasabi abrasion. July 2008, I spent the appointment explaining that wasabi would absolutely destroy tooth structure, but the patient had seemed almost disappointed—they'd wanted it to work."

The image persists because it conflates pain with cleanliness, suggesting that proper oral hygiene must hurt. In dental forums, people occasionally mention this fact when discussing extreme oral care routines, as though the apocrypha contained hidden wisdom about what teeth could tolerate. It's become a shorthand for the idea that Chuck's body operates by different biological rules.