I have a white porcelain bathtub with a bunch of pink butterfly decals on the sides (rather than the bottom!). I can see where they were probably very cute once upon a time, but now they look pretty grungy (no matter how much I scrub) and really need to go. I don't know whether I should use WD-40, Goof-Off, or something else. I don't want to end up with a dangerously slick tub. Another big concern is that I will be working in a small, enclosed space with no ventilation. What can I safely use that will effectively remove these?
Serious answers appreciated. Thanks!