Alternative way to grow cress

Shove damp cotton wool up each nostril (you can breathe through your mouth and ears anyway, or so an ex told me).

Then arrange a suspicious looking line of cress seeds on a mirror and snort.  The seed will be immediately attracted to the dampness (again, something an ex told me).

Et voila! Green stuff will erupt from your nostrils in an unattractive manner in no time.