I once took apart a vanagon reciever- dryer,just to see what what was
inside.  The reciever is seperated into an upper chamber, and a lower
chamber.They are the same size. These chambers are seperatecd with a wire
mesh about 8 gage in thickness. The upper chamber is empty. The lower
chamber contains the desicant. This desicant is in the form of little
balls ,about the size of buck shot. This lower chamber is packed full of
this stuff. All in all , it looks to be a very heavy duty unit. I think it
will survive a roasting. It has a bit of oil inside, so do be careful and
considerate of this when baking. There is no easy way to remove this oil.
When converting to a 134a system , this may be ok. 80 percent of the
systems oil must be removed for proper conversion. If the rest of the
system is cleaned well, the 1 or 2 ounces in the dryer will be
ok.                      As for mineral spirits, works well for me, and is
approved by several sources. I put a vacuum pump on the system for about 20
hours to get all condensables out.I think any alcohol has water already in
it, except for grain alcohol.