Used dryer sheets... I use a dryer bar now (what a great invention) but I keep sheets around for this very purpose. I'm sure you already know that you can stick them in shoes or clothing drawers or even your gym bag to freshen them up BUT did you know that mosquitoes are repelled by the scent? Obviously, if it is a scent thing, free and clear ones won't work but isn't it totally worth the purchase of scented ones to avoid mosquito spray? I don't know the science of why it works; its along the same lines as citronella. Just stick one in your pocket and enjoy a bite free evening! I like to put one between the babies diaper and whatever cute cover I have over it. For people like my oldest child whom are highly sensitive to bug bites, this was a GREAT find! New or used, both work so give it a try!
Also, did you know that ticks don't like lavender or garlic? Want to kill two birds with one stone? Citronella is a actually a rather pretty bush. Plant in beds around the yard, no burning required!