In your engine, there is more than one thing that could be affected in a seized engine. In all my years, spraying penetrating spray on the pistons is futile at best. You need to understand that when the engine loses oil, the pistons somewhat “weld” to the cylinders, the bearing in the connecting rods in some cases can “weld” to the crank shaft and many other parts. I have seen enough seized engines to know that you won’t likely break the pistons loose and even if you do the damage is done and the engine needs to be replaced or rebuilt.
Clean the contacts with either a red rubber pencil eraser ( the abrasive kind) or a small stainless steel brush (very gently scrub the cartridge contacts as to not damage the cartridge) and afterwards take a cotton swab dipped in rubbing alcohol and go over the contacts once again. If this doesn't work, you have a faulty cartridge.
You need to first try to clean the contacts on the cartridge it's self. I suggest getting a small stainless steel brush and gently scrub the contacts up and down. If you don't or can't get the brush, take a red rubber pencil eraser and use it to scrub the contacts. after you have cleaned the contacts, get a cotton swab and isoprophyl alcohol (preferably 80% or higher concentration) and go over the cartridge contacts for the final cleaning. If this fails, the cartridge has gone bad.
Unfortunately this can't be done. The 2GB internal is actually the RAM and is where the apps actually run and will be occupied as you stated. The 25GB is like the hard drive of a computer. The 25GB is only for storage of apps and data. Try running an app that let's you force close apps (Clean sweep or 360 security) and has the added bonus of cleaning the junk off of your device. I run 360 on my phone and it keeps it running really fast.