The tool I use is called Young John!
Had it for over 10years and it works every time.
Drop it off at the job with the instructions - Strip those tiles - and when I come back its done!
The only drawback is it needs feeding daily and expects a wage at the end of each week!
i'm glad i'm not the only one person who uses an old bucket trowel!
minus the handle and a good chap with a hammer gets under most tiles without damaging sub-structure!