It's Darth Vader SHAMPOO.
The Big Bang Theory Season 1, Episode 1
You've convinced me, maybe we should
sneak in and SHAMPOO her carpet.
The Big Bang Theory Season 1, Episode 2
Dandruff SHAMPOO.
The Big Bang Theory Season 4, Episode 1
...and my new dandruff SHAMPOO
doesn't smell like tar.
The Big Bang Theory Season 6, Episode 6
Only to SHAMPOO
Professor Shamburg's shih tzu.
The Big Bang Theory Season 3, Episode 14