Using a sea sponge to wash at a bay, huh? Sounds appropriate
I was the guy at the store trying to choose between the synthetic viking mitt versus the real natural viking lambs wool or whatever it was. Anyway I was torn cause I don't like the idea of cleaning with hair so I eventually went for the fake stuff (seemed softer and longer in nap). I was tempted to go back to my car and do a CD test right then and there.
Which one is the better of the two?
RH my sponge was $2 therefore it is twice as better as yours

with twice as less scratches.