Feliway does wear away, and I think on the bottle it recommends that it be resprayed every three days. Something like that. The catnip spray is a good idea.
In the future, Feliway should be sprayed on walls or furniture at cat cheek height. It should not be sprayed near litterboxes or scratching posts (cat trees). It is also used to help discourage inappropriate peeing and scratching in addition to calming - which means you don't want to spray it anywhere you WANT them to scratch or any place you WANT them to pee. Apparently it works for your kitty, lol!