You can seal it first and put a layer of wax on top, provided that you leave the sealant to cure properly, which would take around half a day, or faster if you leave it under the hot sun.
I've tried the Skil polisher before. You can say that it's an 'entry level' rotary polisher. Performance is about the same with the rest of the C-made, al-cheapo polisher. It works but, unlike the Makita, DeWalt or Hitachi, it'll bog down under pressure/load, so you'd need to put up a little extra effort and take the extra care when using it. But if you're not ready to fork out the $$$, and would only be using it occasionally, it's a good option to consider.