Shaggy rug Pet-friendly alternative to a shaggy rug for room acoustics?

simple. Audio room is a pet-exclusion zone.

@triskadecaphobic 

These are all relatively thick-pile washable rugs.

https://www.wayfair.com/rugs/sb2/thick-pile-washable-area-rugs-c215386-a1500~512794-a2959~431184.html

Besides pile height you want density, which is why a thick, cut-pile rug with a felt pad is considered a good choice. Wool fibers absorb sound better than synthetic but obviously are not as easy to clean.

@audphile1 

+1

I would lay down some absorbent pads and train him

secret is to walk the dog multiple times per day and not wait until he accumulates enough to wet the pads or the floor. This means walking him 5-7 times per day. This is how he will get trained to pee outside only.
Then gradually remove the pads and only have them on the floor for emergencies if you can’t walk him.Good on you for saving the pup!

You should look at those "Waterhog" rugs. They are bulletproof and you can hose them off, let 'em dry and repeat whenever you need.  Rubber-backed also so no leak thru. 

A Dog Grooming Parlor will be able be a great help.

Book an appointment to drop the dog off and do meet the appointment and deliver the dog.

Request a return to pick up the dog in 2 Hours.

Head on to a airport and go on a Holiday for at least two weeks, on the return home problem is solved.

Otherwise get a doggy catheter and the mutt can wee where ever it likes.