Hi
Ive not got any of above or similar techniques to work yet, but my interim solution may help a little and you only need the factory box SD card and a PC, even the PC should be optional, but harder work.
Ive got the new Ace variant, and suspect the root process needs to be bespoke... but doing following you get nearly double the memory YMMV, but it is easy...
You down load your favorite apps until you get error memory full. You may have done this step already already?
Next you save about 80Mb by...
going to settings/applications/manage applcations/ and delete
the playstore services and playstore (updates) note playstore will still work (ie download) as per normal in its fresh from factory state if you need it again, while away...