I did both. Originally I used the Seals from Hunts for Sands until I had broken all of the gear I needed to, then I started using seals for Oils. In the mean time while gathering the sands I did ST for an Oil every week. It took me about 1-2 weeks to get my job entirely maxed out on both. Mind you I was doing hunts alot. Even so, it doesnt take very long to break all your gear even if all you do is join in on the S ranks.