Architectural detail: Cabinet latches Part II

Previously, I posted an entry about icebox latches on cabinets serving as child-safety latches.  Then last week, Remodelista had a post about cabinet latches in general.  I thought this one would work pretty well as a child-safety latch.

[Bar Latch]

Maybe an elastic band looped around the little knob would be sufficient?  How smart/dexterous are young kids?