MVB = bottom rack of the dishwasher!!!
downtube and slide goes in the delicate rack in the forks and knives.
i only load my bong when its ready to go so nothing can get accidently bumped in to it.
if you have pyrex or myrex glass you can dishwash them unless you have scrubbed the inside of your bong...
the scrubbing puts small pits and scratches in your piece which allow tar/resin to build more readily making it extremely hard for the dishwasher to clean it all out.
the scrubbing will slightly weaken the bong and could cause a stress point in the glass to rupture during heating in the dishwasher.
if you get a new one dont put it in the dishwasher if it isnt PYREX or MYREX.
hope this helps.
P.S. i wash my pieces once a week.