When the floodlights come back on in the stadium after Batwoman fights Tim Teslow, the row of tackle practice pads (one of which Batwoman was knocked into only moments earlier) has disappeared completely.
When Mary suggests crushing the Kryptonite, Luke looks at her like she's an idiot and says "with what? A hammer?" Breaking strong crystalline minerals with hammers actually works quite well; it's how diamonds, rubies, and other valuable stones are both cut into gemstone shapes and ground (crushed) into powder for industrial uses.
Luke has tried various powerful acids to dissolve the Kryptonite sample, including sulfuric acid, hydrochloric acid... and acetic acid, otherwise known as common vinegar. But he makes no mention of the truly powerful, all-consuming acids such as aqua regia or hydrofluoric acid.