Likely at this point you'll need new pads since the hand towelettes will likely have put soaps and moisturizers onto the pad linings as MudPie mentioned. Once on the pads it's very hard to get some of that stuff to go away.
A last ditch try for your case would be to remove the pads, sand off any glazing so they are dull on the face then boil them in regular water for an hour or so. While you're making the "pad soup" use some 320 wetordry silicon carbide sandpaper to scuff up both sides of the rotor braking surfaces. And don't sand "around" the rotor, you want lots of cross hatching lines. So sand in small swirls or in tangents to the rotor. Following that clean the rotor with either brake cleaner or the rubbing alchohal on paper towels. Keep flipping and using new ones until the cleaner or alchohal on the towel does not come away with any staining at all. It's not even a good idea to touch the rotors where you can help it since your finger oil can even be enough to cause a problem if there's enough of it. Install the boiled pads and try it out. At first I'm pretty sure you won't have any squeal. But as the cross hatching wears and the pad faces burnish up again the squeal may come back. If it does then you need to get new pads. And contrary to MudPie's vote for OEM pads in this case you don't want the same material over again. Go for a good aftermarket company such as EBC or Koolstop instead. Squealing is about the friction between the pad and rotor metal having a hysterysis. That is, it grabs, jumps a little than lets go for a millisecond then grabs again. It's the same effect as we see on violins or rubbing a wet finger on the rim of a wine glass. And it's caused by a particular frictional charactaristic between the pad and the rotor. Change that balance just a little and the effect goes away and you have silence. The sanding and cleaning will alter it for a while. But if it comes back then you need to alter something in a more drastic way. Hence the aftermarket brake pads.