Checked out the 38 members in Hong Kong. With one exception, all the long-inactive accounts were either 'my country only' or 'ask first' so mooching/vacationing was not an option. My solution was to send this email to the 19 members listed below:
Hi, I'm working at a project aimed to review BookMooch inactive accounts and helping users without activity find their way around the site. You don't have to do anything, but if you are interested in participating, I would be happy to answer any questions you might have. If you find Bookmooch does not meet your needs, you may prefer to simply close your account. Thanks in advance
Donna, I took the liberty to add the links so we could easily check if they have logged in recently. Let me know if you hear from any of them. I'll try to find an angel in Hong Kong in a few days for the ones who don't respond.