Can soapy water kill my red eared slider?

I just bought a new tank but it had some strange dusty stuff on the sides that wouldn't come off with just water, so I used liquid soap (like hand soap). I can still see a little bit of residue, and no matter how much I rinse it, it won't go away. Will my turtle be okay? I have a filter which is currently running. Should I let the water filter for a few hours before putting him back in the tank? Thanks