Tergikleen or AIVS formula 15?

My set up is similar but without an ultrasound. Over the past 50 years I have gone to the less chemicals that touch my vinyl the better. I use Tergikleen (20 drops per gallon) (or Photoflow) in a SpinMaster, too. Whenever I buy New brushes for the SpinKleen I reserve one. I use a "new" brush and and older brush, and flip the record halfway through my process (anywhere between 12 full revolutions- and whatever might be needed. I rotate in both directions). I rinse with distilled water from the grocery store over the kitchen sink using a pressurized spray bottle. I dry/ final clean on a Record Dr., once again, rotating both directions, maybe a total of six to 10 rotations per side, and finish air drying with a bamboo dish rack. I pre-clean with a shaving brush, and use a Zerostat for obviously charged records. New inner sleeve and a quick note on the little yellow sticky with date cleaned, condition, whatever. New outer sleeve, if needed, and then back into the rotation. I don't think that there's anything more personal in our world than our record cleaning technique. Maybe stylus care comes close. My changes now are incremental, maybe a new style of label protectors, different "examination", or curator's gloves. Maybe I should start a Go Fund Me for a Degritter...I would only mention what I do, and never tell what I think you should do. It's a journey, not an assignment.

Interesting. I'm not sure what purpose having an old and new brush serves, other than needing to buy brushes less often. 
I also give them new sleeves and a sticker with the date & fluids used. It's the Engineer in my bleeding over to civilian life 
I used to use a method similar to yours with the Spin Clean and Disk Dr. It's not bad for the money invested, but now I prefer not to have the record touching the lips of a vacuum machine after it's clean. Possibility of recontamination bothers me. 

Have your tried the Ai fluid in the spinclean?

You need to do a side/side comparison. That is hard to do, can you manually clean one side with X and the other side with Y then listen? 

With your Degritter after, not sure the pre-clean is as important. Do you use anything in your Degritter? that also make a huge difference.

I would just do what is most convenient for you. My cleaning is also a 2-3 step process, with a manual clean before UC. If it's really dirty, will do both steps twice. 

I would but formula 15 is not a concentrate. It would take the entire bottle plus some. 

In the Degritter I've tried the new version of the fluid that ships with it, but the AI concentrate that's made for US cleaners works better. After that, I have a second tank for the rinse with just distilled water.

ENZYMATIC RECORD CLEANING CONCENTRATE FOR ULTRASONIC RECORD CLEANING MACHINES

I used and liked AI products for years. Deep cleaned some records recently using Walker enzymes, then Pro-Ject vcm, then a rinse, then into a Degritter II, then a final rinse on a Project. Noticeably quieter surface noise.