LOL Brody and Mia, who is very hyper and incites Brody, do not touch the floor in any store. They go into a cart on their memory foam pad. But, before we got Mia, we did let Brody walk several times in Petsmart...so he could explore. He peed once and pooped once...we cleaned the floor...and has ridden in a cart ever since...not so much because of the elimination...because we rounded a corner twice right into a huge dog. One was an Irish Wolf Hound...who are generally very sweet...and was letting all the kids pet him, but who bristled when he saw Brody. DH scooped him up immediately and whisked him away...and he has not touched a store floor since then.
However, we have to be careful in places like TJ Max...not to let him see us handle toys. He is very toy centric and if he sees it, it's HIS...and he will start barking if he really wants it and thinks you are going to put it back.