Supposedly, Amsoil no longer markets a grease that is suitable for use in CV joints. I would use Redline CV grease.
Given the age of the vehicle, it may make sense to remove the axles and install new boots. Toyota makes a really nice CV Boot Kit for around $30/boot.
2011 Toyota Prius - 170k - ServicePro Dexos 0W-20
2007 Honda Accord 2.4 - 129K - Idemitsu 5W-20