This is from our first year cleaning. Thought this would be like any other and we did not know the buttons were metal. The guy told us they used to spray the couch off with a hose. When we cleaned it, 2 hours later they sent this picture. From then on, we've always covered the buttons and didn't get any moisture on them, maybe small spot clean w a brush.
Shit about this f*{^} couch, the customer thought they bought it from RC Wiley when eventually found at it was bought at Z Galleries. When we were trying to find the exact fabric color and type, it took weeks, then had to order it from Great Britian on top of reupholstering the buttons. T-Rust couldn't fix that, the rust fully ate away the fabric.
I told the customer they could have been rusting under neath when washing w the hose. (This was a high end home to). We still took responsibity in fixing it. $350 lesson.
This pic was from the customer 2 hours after cleaning. I don't know why those buttons rusted only - we cleaned the entire couch.