Man I used whatever was in my grease gun, and it was the cheapest stuff I could find at the parts store, I have no problems, and I've done a couple of cars!! And I never torqued any of it to spec, however hard the bolt was to get off I put it back in that spot, my complete rear was done this way. No problems, and again I've done several cars.
I highly recommend that you remove and clean those bushings.
Someday you're going to have a massive clunk, and when you look at your bushings - they wont be there.
Petroleum based grease is not a good choice with polyurethane bushings. It will permeate, and cause the bushing to distort/swell and split, if you are lucky. Most of the time, it will cause the bushing to just start crumbling away, piece by piece.
:beer: