Luis,
1. Feel free to use faderlube if you want.
I do not choose to use it because it contains a lubricant as well as cleaner and the lubricant will leave residue. That residue may not matter for years, but why chance it? I'm pretty sure the pots were not lubricated when new and it is now approximately 50 years later and most work.
On the opposing side of the issue, the lubrication may be good for a stiff or dry pot(entiometer) and I do have, and I do use, faderlube when I have a stiff or dry pot.
2. Deoxit D5 is too expensive to use as a rust and corrosion remover except in pots and other hard to reach locations that would need it.
The advantage of any of these sprays is that you can reach areas that a swab or a rag will find find it difficult to reach or will never reach.
I have been fortunate enough to find both lubricating and non-lubricating electronics spray cleaners that do not have the name DeOxit and therefore are considerably less expensive to purchase and come in considerably larger cans.
3. On the use of isopropyl alcohol, feel free to try it and let us know how it goes. I do feel that alcohol often has drying properties and that can be good or bad depending on where you use it.
Best Regards,
Don