Szwab is so passé, these days it's niemiaszek or simply Fritzl.
Really?
Niemiaszek - as diminutive - was popular in Polish movies from 60'. Russian soldier used to say:
szczęśliwie wyrżnęliśmy wszystkich Niemiaszków = fortunately we have all Niemiaszeks butchered.
Fryc (not Fritzl) is as old as
Szwab and
Szkop and is 100 yo or more, I believe.
More contemporary was
Helmuty (Helmuts - after Kohl and Shmidt) for Western Germans - not derogative
and
Enerdowcy - after
Enerdówek (let's say Ddrdorfers after Ddrdorf) for Eastern Germans - more paternalistic than derogative.
I haven't heared any new derogative term for Germans since then. It looks things are getting better at last in Poland.