We are considering selling our timeshare in Key West and would prefer not to use the resort sales person for obvious reasons. Since we wouldn't be able to have "showings" like the sales person would, I assume that anyone who might be interested in purchasing would have to already know what they're getting. Correct?
I would assume no such thing, frankly. Someone seeing whatever ad you place might like the
idea of owning a timeshare in Key West, but they may know absolutely nothing about your particular resort (or its' maintenance fees, reservation policies (if not a fixed week), how a week is defined there (Saturday to Saturday, Sunday to Sunday?), transfer fee amount and who will pay it, exchange company affiliation(s), unit size, amenities, resort location within the nearly 5 mile long island (proximity to Old Town), etc. You should be prepared to provide all of this kind of information in clear and specific detail to any respondents to whatever ad you might place, wherever you might place it. Some inquirers may know quite a bit about these details already, but I wouldn't make any such assumption. Be ready to provide informed, accurate answers to questions posed by prospective buyers.
Since you evidently intend to sell your interval on your own, you should also give some advance thought to selection and use of an established and reliable third party closing entity (such as LT Transfers), as well as giving some thought to who (i.e., buyer or seller) will be paying those costs.
Consider too that you
could have an interested party who asks "So....just how do these timeshares work, anyhow?", in which case you would have an additional educational burden on your hands, if you are even willing to go down that road.
The good news of course is that
most (...not all, but certainly most) timeshares in Key West tend to be desirable and consistently in demand.
If priced competitively, you should have little difficulty selling, although (IMnsHO) Coconut Mallory might very well be a noteworthy exception.