FUBAR , 

   When I use th Vallejo Primer I'll drop a lil' bit of Their Thinner( 17ml Black Cap) in th cup with it  & I actually shoot it at 30psi , sometimes ya gotta be quick when trying to cover a tight spot, but ... 

   I also keep a #0 , or #1 brush handy & dip it in water & just run it around th Needle of th AB to clear it out. I think if you use AB cleaner , you may inadvertently shoot it onto th Model   , at least with th Water , it'll just come out a lil' thinner ......   Just a thought .