That's because Canada Post isn't legally allowed to open your packages. If they have a suspicion about a package, they can alert the authorities to handle it; and of course the CBSA can and will open anything coming into the country. I guess the big question is; "are you willing to get caught?". You can however mail an airsoft gun, or the belt itself. Or if the object can be disassembled into small non distinguishable pieces then "technically" it should be fine.
ďREALITY IS LIKE A STONE. TO MANY ITíS HARD AND COLD, THEY CANíT HUG IT OR EAT IT, IT ONLY FRUSTERATES THEM AND DOESNíT DO THEM MUCH GOOD. TO OTHERS ITíS STRONG AND DEPENDABLE, YOU CAN BUILD WITH IT, BUILD UPON IT, OR WORK WITH IT, ALSO USE IT TO SMASH PEOPLE IN THE FACE.Ē