I've been into high performance cars and audio since the 60s, and can say without hesitation that after I wash a car it goes faster. Dirt particle drag? I suppose...Also note that I never wash my audio gear...a little dusting...damp cloth to remove a smudge...
The Emperor Has No Clothes!!
Read a post the other day where someone characterized a server/streamer as “sweet and tube-like sounding”. It read like a parody. Am thinking of starting a company based on tube rectified power supply for network switch. Crowd funding?