If you have an "innie" then it's prob just from sweat & yes, lotions, etc if you use them could have a factor in this too b/c it can 'settle' in the navel so if you don't get it out, it can get all gunky & smelly, at least in my experience b/c I sometimes have the same issue so the best thing to do is just wash it out daily when you bathe. Just take a finger w/some soap (pinkie finger seems to work best w/me), rub it around in there then rinse w/the shower water...might be easier if you have a detachable shower head or point your belly button upwards towards the shower if you can & let the water run in/out for several seconds. When you get out of the shower, take a q-tip & gently rub it around in there to dry or take a hair dryer on 'cool' & dry it out (the 'heat' setting may be too hot). That's what I do...you're not alone trust me! Hope this helps, good luck!