All wire benefits from a clean and titanium has either titanium oxide (not titanium dioxide) on the surface and graphits is used as a lubricant with Ti drawing (I think)
We give ours a polish with 3 sets of felt pads which takes off the majority of any dust or oil. I've got some photos on a different machine I'll post shortly. I make a point of changing the felt pads regularly with new ones I make myself out of sheet felt.
For certain wires like ni200 ribbon, the wire can be noticeably oily so those spools are soaked in containers of isopropyl alcohol for a few weeks the respooled while they're still wet helping the felt pads catch the oil. In the case of Ni200 ribbon and Ti wire we also white glove the wire as it's fed through the respooler. It's actually quite handy doing that to control the wire tension too.
Our Ti is certified medical grade and we've published the datasheet. The main things that makes grades 1 to 4 titanium differ are the gas levels. Oxygen levels are of interest to us because with the potential worry of TiO2 forming on the wire surface the amount of oxygen present in the wire will greatly affect the rate at which it oxidises.
So less oxygen the better.
In the datasheet you'll see the target gas levels and the actual gas levels.
Medical grade Ti seems to have much lower gas levels.
We were a bit hesitant about selling Ti wire so bought the best we could. Of particular interest is the finish. Ours has a finish that's called bright. As opposed to acid washed. It's our understanding that bright Ti wire has a further advantage to acid washed with regards to oxide formation.
All titanium annealing is done under vacuum or in an argon filled furnace btw. Some vendors seem to make a marketing point of the annealing process to make it sound more special than it might necessarily be.
Ultrasonic cleaning, now that's an idea. Something so obvious I can't believe I'm not doing it. And I will.
So, to recap medical grade 1 is better than grade 1, at least on paper.
Different finish as far as I know to all the other Ti wire out there
It costs more
We give it a polish
And some love