GM 3.8L Supercharger Squealing/bad oil

Ok, so I inherited a 2000 Buick Park Ave Ultra from my grandmother. It has the supercharged GM 3.8L V6.
It has 85k miles and is in immaculate condition. The supercharger has recently been squealing which lead
me to research that it takes oil and it probably needed replacement. Ordered the appropriate oil and went
to change it only to find NO oil, only resin like sludge! Literally sat there with a straw taking "core samples"
of gawd-awful crud out as best I could and even hooked up a small shop vac to the straw to suck
everything out.
I will consult a mechanic but really don't want to get screwed on a costly repair/replacement. My questions
are - Is this a sealed unit? Can it be opened up and cleaned? Is there something I can use to flush the crud
out? I've thought of adding the fluid and getting more and running it then removing/replace/repeat.
I am mechanically inclined(replaced a rack and pinion before, did a full suspension lift on a Jeep) so am
confident in my ability and have the tools, but I really don't know anything about this supercharger system
and have been unable to find specifics related to my issue online. Any information from someone who
knows the proper course of action would be so greatly appreciated. Thanks!