Suggest do the least imposing first:
Remove the atty and blow from cart end first into a paper towel near the threaded end. Do this a few times. Try out the atty. If no go, blow from the other end (threaded end out toward the cart end) a few times into paper towel. Then try the vg or pg and if the taste is still there go with 151 vodka the cheap stuff pure grain alcohol - I have "Galen's" 151 charcoal filtered uncolored unflavored. $12 and worth having around. You can also use this (or Everclear) for cutting VG if you do DIY
juice.
Just put some of the vodka in the chamber, and bridge - shake and blow it out, let dry, etc. If no go - soak it for an hour.... this is only necessary with some new attys with nasty primer fluids and some need none of this at all.
edit:
I might point out that I've had two BE510 (SLB's?) that I have that no amount of washing in vodka helped removed a metalic taste. I don't know why that is.