Somehow the porcelain waste pipe of the toilet has cracked and has started leaking. We're about to replace the whole bathroom so I just need a quick fix. Will wrapping the crack in duck tape work?
Epoxy putty, found in the plumbing repair section or adhesives section of your local big box store:
It's a two part compound that you work together like clay. Blend a small amount, per instructions, then force it into the crack, ensuring it completely fills the crack.