Yeah yeah, its the same as that sugar thing.

A kiko of sugar can ruin a thousand kilos of concrete. A thousand kilos of concrete is a small part of a wall. Anyone trying this will immediately be caught because they'll immediately see something is wrong and at best you'll sabotage a tiny part of a single wall. You'd set back construction maybe maybe by a day and for that you'll be tried for terrorism or something

All in all very impractical