[OT] Magnetic sheet question

For those of you who have used sheet magnet material:

If I cut a round penny-sized chunk of this stuff and affixed it to the
bottom of my figures, would it provide enough strength to carry my
figures using a case with some iron or steel strips along the bottom? Or
would the bond not be strong enough to hold them upright? 

I'm more interested in this for tree basing than anything, as my 6" high
trees are a pain in the netherspaces to pack, but I would be interested
to know how it works for 25mm figures too. 

Any information/experiences appreciated!