I am having a wand made and I wondered what the best finish would be. Money is not an issue, and neither is skill. I do not care about the aesthetics (color/scrapes), but need it to not come off. Im not going to be refinishing it. It would not be exposed to sun often, but may be taken outside about once or twice a year. Thus it would not experience much weather change because the house stays relatively the same temperature. However, it would be exposed to humidity and wear from hands. Can varnish wear off by rubbing? I need the strongest finish for these specifications. Any recommendations? I would need a type (example: water polyurethane) not a brand.
General point first, there is no best finish for any job because part of what constitutes 'best' is down to the taste of the individual, which is obviously highly variable.
In addition to that practical considerations come into play for the woodworker, a high-end finish that gives excellent performance might not be picked on the basis of its high cost or because of a short shelf-life (too great a potential for waste). Another reason could be simply down to an issue with application, either it's too challenging to apply well for the project at hand (e.g. superglue finish on intricate carving) or where a finish must be sprayed and there is no spray equipment available.
but need it to not come off.
Just remember that everything has a finite lifespan. No wood finish is 100% guaranteed not to fail, ever. (But see last point below.)
Can varnish wear off by rubbing?
Yes, but strong varnishes are highly wear resistant — as seen on the edges of dining tables where wear-through can take years of regular use.
I need the strongest finish for these specifications.
Perhaps you don't. Instead consider whether a finish that is easily repairable would be better, so with regular upkeep — easily done by the user, not the original woodworker — you continually restore it rather than attempting to rely on a film finish that will fail eventually (even if after many years of service).
There are two good options in this area that are widely available, relatively inexpensive and easily applied without prior experience: boiled linseed oil (often shortened to BLO) and tung oil (must be pure tung oil, not "tung oil finish" which may contain no tung oil at all).
After the initial finish is built up over a week or longer of daily applications and buffing, a couple of additional coats in the first year and one coat per year after that will maintain the finish in good condition for decades, perhaps indefinitely if upkeep is maintained.
Almost everything I turn I use Carnuba Wax, it is mixed with mineral spirits to make it softer and easier to apply, but once dried it is the hardest natural wax out there and is supposed to be hypo-allergenic. It's also easy to reapply if you feel the need.