HTML and Media Objects

Whether using NT or not for your JAS platform, your media objects are cached in whereever the MOQUEUE is pointing in your jas.ini. My question is, when do these get cleaned up? Is it when you cycle the JAS server? Is it safe to go in and clear them yourself?

Thanks in advance.

For this case (ERP8.0, 2k, SQL2k, JAS, SP22_D1)