Laptop or other flat object

The wand need not be disguised as a rod, if it can be hidden in a flat object. This opens up laptops, books (a big Bible would do the trick).

Those sticks that girls put a couple of through a bun or topknot

My hairdressing acumen isn't great, but it would work. If the gem has to show, this is a good option.

Necklace

Depending on fads, a necklace could incorporate a rod, either hanging or as a central spar for a whole lot of metal bits to hang off

Cross / crucifix

For places where a mastubatorymasturbatory aid won't be allowed in...that also aren't in Saudi Arabia.