Since you bought the paper secondhand, that is indeed a possibility; however, don't ditch it just yet. Different papers often require slightly different development times, so it's entirely possible that you underdeveloped the satin paper and properly developed the pearl paper.
I know that both HC-110 and Rodinal (R09) can be used as paper developers; however, as this thread indicates, most people prefer to use developers that were created with paper in mind. There's nothing wrong with experimenting with HC-110 or Rodinal/R09 on paper, but for learning I certainly concur with the others who say you should try a common paper developer. Note that development times vary both between papers and between developers, so development times for Developer A may be off if you use Developer B.

