jaja this is very common after sandblasting
kerosene or solvent flushes, many of them
use a coffee filter and STRAIN the solvent
you must do this until the coffee filter and solvent comes out clean...something like 20 flushes moving the frame all around
use 1 liter of solvent every time, buy 3 or 4 galons of solvent(kerosene, mineral spirits, thinner, acetone etc...) it needs to be thinner than oil obviously
steve has a nice pic of this method on his engine rebuild thread for an xrl.