In the 70's, I saw Stravinsky's The Rite of Spring at the Edinburgh Festival. The whole stage had been covered in dirt, and the sweatier the dancers got, the muddier they got until it looked more like a mud-wrestling match than a ballet.
I went to a production of one part of the Ring Cycle at the Paris Opera House (drop-a-name) some years back. To be "with it" and hip, the only stage set and/or decoration, were stacks of plain stage sand bags, in various sizes, with bare light bulbs on the floor behind them.
They led "whoever-soprano" in on a real horse, and within minutes the horse had kicked or stepped on several light bulbs and they burst with a popping sound. Thankfully, the horse didn't spook. But some of the audience did, and left.
HIDEOUS production.......... GORGEOUS venue!!