Well, can't hurt to try!

Actually the joints should be fine as long as you change the boots before they fail and allow crap to get inside....

A

PS I read the CPO warranty and it doesn't exclude boots... but it does exclude all items that might fail due to normal wear and tear. And if a boot fails due to aging rubber, then the CV joint fails- and they decide they don't cover the boot you are stuck on the joint. just call up your friendly SA and ask them a hypothetical...