Hyrdogen Peroxide is less harsh and will also break up super glue.
Where can I find it? (Currently staying in Taiwan).

Any medical store/superstore should carry it, probably close to isoproply alcohol. The chemical name is H202. If you can't find it in a store go to a clinic/hospital and see if you can borrow/buy a bottle from somewhere.
I wouldn't use acetone as the upper is synthetic and I'm guessing probably contains some plastic which would melt w/ acetone.
When using the hydrogen peroxide use it in an inconspicuous part of the upper first as it has some whitening/bleaching properties.