How to DEFORM to sphere ?

[micheus]

I already heard about this before - it has exactly two years (here).

Well, it was not done exactly for this purpose, but I think you could use Stamp mode I had implemented for Alpha Brush option of Sculpt's Optigon plugin:
www.youtube.com/watch?v=2f_Gru6aHWI

You can find it on my Google drive: W.I.P/Alpha Brush