have to disagree, but perhaps others that do this a lot more than me (the mechanics who have posted here) can chime in. I find that using my fingers I can be sure and feel that it seats properly and goes in well. I know there is a doohickey that makes it easier, but I change chains so infrequently that I havent bothered getting it.

I'd be concerned that vice grips could force it if it isnt properly positioned, ie squeezed inwards properly before pulling back.