How to teach paw targeting to a dog that likes to use his mouth/teeth...

I was trying to teach Blake paw targeting by using the lid of a jar and hiding the treat underneath it.  The problem I'm having is he LOVES to use his mouth, nose, and teeth to investigate things and if he really wants something I know that he will use his teeth to bite at it.  He will sometimes use his paw to scratch at the lid and quite obviously my hands and fingers get in the way of all that and I end up getting some pretty scratched up hands lol.  I figured maybe I need to use a bigger lid but somehow I don't think that's going to work either.  Is there any way for me to be able to teach him paw targeting or do I have to wait until he's older and out of the mouthy phase?