it works when applied regularly

First we had the scent of Feliway plug because our cat has marked at irregular intervals protest. The plug was working 12 days without any problems, then the hangover has just marked next.
Since then we have switched back to the spray and there were no more problems. One has but to apply regularly. We use it every 2nd day's visitation after every 3 days and since then peace. You should apply it whenever the cat 10 minutes is not get there.
I think as a human being you can smell the spray almost did not, but it does not smell unpleasant.
For each of a protest-marker has I can only recommend the spray.
Meanwhile, we have run out the spray slowly (until it was empty) and there was so far no more additional markers.