This is a picture of Winston (serial marker) in his belly band. After 6 years of marking, this has been a great solution for us.
I found these at chewy.com. They are washable and haven’t leaked. Our routine after removing a soiled one is to spray some enzymatic cleaner right on the soiled spot. We then keep them in a pail in the garage until I’m ready to wash them. When washing, I turn them inside out, making sure the velcro is fully closed so it doesn’t gather lint, which might make it not stick as well in the future.
These bands are allowing the dogs to have free run of the house, instead of being gated in the den and kitchen.