A. Muzi wrote in part:

Spread cement in an area slightly larger than your patch as
thinly and evenly as possible while remaining wet. Allow an
angel to pass. That in this case is ten to thirty seconds
until the glue looks dry.

You can't patch a tube on the road that way.
It is absolutely necessary to let the glue dry
completely, which means a whole gang of angels
must pass before applying the patch, say three
minutes or so.

Robert