Sorry to break the bad news here, but you NEED to get that stuff flushed out properly and quickly. The parts in this system can be expensive and all are at risk with the use of pas fluid.
See the 20v.org links for flushing procedure and more info

http://20v.org/pentosin.htm

By the way, Pentosin is an American brand not usually available here.


http://20v.org/brakprob.htm
Brake & Hydraulic Problems

The system is probably very similar to if not the same as the 20v if the 16v has hydraulic brake assist. Either way, the PAS system should need to run the mineral oil, so you need the flush the system regardless.