Towel Bathing is when someone bathes while they have a towel on. This is mostly done in Hot Springs.
801 TTS Airbats
The fourth episode of 801 TTS Airbats has Miyuki Haneda and Yoko Shimorenjaku bathing in a Hot Spring while wearing towels. Miyuki's towel is white and Yoko's towel is yellow. Arisa in the background went with no towel.
Arakawa Under the Bridge
Nino bathing in a barrel wearing a pink towel
In the second episode of Arakawa Under the Bridge, Nino bathes in a Barrel while wearing a pink towel.
Ami bathing in a fake hot spring wearing a towel
In the eleventh chapter of Digimon Next, Ami Kitajima bathes in a Hot Spring wearing a towel. When she finds out that it was an illusion and that its really oil she is still wearing the towel.
Tsururin in the hot spring wearing a towel
Akane and Tsururin bathing in towels
In the 51st episode of the Dr. Slump remake Akane Kimidori and Tsururin Tsun bathe in a Hot Spring wearing white towels.
Neon Genesis Evangelion
Asuka, Rei and Misato in towels while in bathtubs
The Evangelion soap trays feature each of the girls bathing in Clawfoot Bathtubs while in towels. Asuka Langley Soryu is in a red towel.
In the 58th episode of Pokemon, Misty bathes in a Hot Spring in a pink towel.
In the seventh episode of Zombie-Loan, Michiru Kita bathes in a Hot Spring twice. She wears a white towel during her second bath.