You should remove the Vive Deluxe Audio Strap cushion to clean it.
VR Cover Deluxe Audio Strap Foam Replacement for HTC Vive : : Video Games
Replacing the face cushion
HTC Vive Deluxe Audio Strap Foam Replacement 20mm - VR Cover
Headset Adapter For Connecting Oculus Quest 2 With HTC Vive Deluxe Audio Strap
HTC VIVE デラックス オーディオストラップ - PCゲーム
Attaching Vive Deluxe Audio Strap to the headset
Attaching Vive Deluxe Audio Strap to the headset
Adapter Compatible with Meta Quest 3 Accessories, Perfect for Connect HTC Vive Deluxe Audio Strap Adapters and Quest 3 Replacement Strap : Video Games
: Video Games
HTC Vive Deluxe Audio Strap
HTC Vive Pro + Deluxe Strap Mod - iFixit Repair Guide
HTC Viveデラックスオーディオストラップ