Can you smoke weed out of a dab rig?

You can smoke weed out of any dab rig and you can smoke wax out of any bong water pipe.

Will you get the best experience? 

No

But you can do it.

Rigs generally have a smaller volume and less filtration so generally you don’t want to cool/filter the vapor too much or it will turn back into a solid (ever see peoples rigs that have wax floating in the water?)

Bongs on the other hand are designed to carry combusted flower smoke into your lungs so they should have more volume to allow more water and a chamber of clear space above to build up smoke inside for you clear all at once. It should also have a steam that diffused so it can break up the smoke into thousands of tiny bubbles so it will filter and cool down that harsh smoke and make it smoother so its more enjoyable for the user.

So you can see the dab rig and bong are pretty much exact opposites the only thing they have in common is they both hold water, and diffuser and a glass joint.