I have not tried the oven method and probably will not since my oven does not vent outdoors. For the tough glue left behind after scraping I generally use Acetone which does a reasonable efficient job of getting off the the gummy stuff. However, I ran out this weekend and substituted Mineral Spirits (because I had a can on hand). The mineral spirits seemed to actually do a better job than the acetone, but it left behind a slightly greasy film that needed additional wiping to remove.
I think I like the spirits better, but I would like some other folk's opinions. After de-labeling, my bottles usually sit for a good period of time and will get a complete wash/sanitize before being put back into service.
Is there anything I should be concerned about by using mineral spirits?
For cleaning off what oxyclean does not handle, I have definitely found mineral spirits more effective than acetone. But personally I prefer carb cleaner spray, which is more volatile, and hence easier to get rid of, than mineral spirits.