Fix for old Elite figures with squeaky joints?

I've been going through some of my older Elite figures that I came across after just moving and unpacking, and I noticed there are several figures with stiff and squeaky joints. E14 Kane, Legends 3 Rock and DM2 Triple H, specifically, are the worst. Does anyone know how to fix this problem? I thought of possibly using wd-40, but I think that could potentially make the joints too loose and oily.