I've never been much into cloaking so I can't answer much about that. But if there's a link I'm going to use a lot I'll create a sub folder on my server and use a meta refresh tag so I don't have a messy URL to remember or type.
So my URL ends up being something like
http://www.mydomain.com/folder and that redirects to my affiliate link. But I do that with many affiliate links, not necessarily SiteSell's. Depends on the situation. Just for the record, that's not to hide the link, it's for easier link management. That way if I ever decide to change the link I only have to update one file instead of updating all the links throughout my site.