I think OP is confused about what the ESN is... You don't "clear" an ESN... It is simply the serial number of the phone as Verizon's network sees it. An ESN can either be good or bad. If it is good (like most of ours), it can be activated with Verizon. If it is bad (usually because it was reported lost or stolen), Verizon won't let you activate it. So I assume you have a clean ESN, and definitely mention that in the listing.
But definitely use eBay or Amazon. And I would write down the ESN in case you don't receive payment or something crazy happens like the guy who buys it changes the ESN to try to get it working on Sprint, then sends it back saying it won't activate. Then you can at least try restoring the ESN to original, or maybe have Verizon do something about it, I don't really know how that works. But ESN modification is frowned upon by carriers, I think it's legal though, just cloning an ESN so that two phones are on the same network at the same time for the price of one is illegal. If that makes sense.