Googled 3M 9460
When "3M 9460" was searched, a PDF file of 3M Technical Data showed some application tips on page 4 of 4. A clean surface was recommended with the cleaner being isopropyl alcohol/water or heptane. Let's talk about those two cleaners.
Isopropyl alcohol is the chemical name for rubbing alcohol. The drugstore has it in 91% and 70% alky/water ratio for about a dollar a pint. IIRC, isopropyl absorbs water vapor from the air so it is never 100% alcohol. No, you do not need to thin it with water, the water mentioned is just already in there as it comes out of the bottle. My opinion is that is an inexpensive cleaner if it is suitable for the cuben.
Heptane is a refined petroleum product like a super clean gasoline and likely smells that way. Not a pleasant solvent to work with. I'm guessing that is what the stinky "94" 3M solvent is. My question is, is 94 necessary for cuben, or is that just 3M upselling their product when cheap iso alcohol is adequate and smells slightly better?
The application tips also mentioned pressure would improve bonding so Sgt. Rock's use the roller not only pushes out bubbles but matches 3M's bonding advice. At BPL forums, Steve Evans weights/squeezes his bonded seams while they cure for a period of time. As an engineer, he may even understand some of that lingo on the tech data page.
As part of the same Google search, Amazon.com has 36-yard single rolls of half inch, 3/4 inch, and one inch wide 9460 tape for $25/$36/$49 from CS Hyde with free shipping. RS Hughes is not the only retail source. A case of each type of tape is over a thousand dollars direct from 3M.
Just telling you what I saw on the internet.