Grassl rhymes with:
gracile, grassel, brasel, brasil, brassell, gracile, grassel, astle, basle, brasel, brasil, brassell, cassel, cassell, castle, facile, gracile, grassel, hassel, hassell, hassle, kasel, kasell, kassel, kastle, tassel, vantassel, vantassell, vassal, vassel
Grassl sounds like:
garagiola, gargill, gargiulo, gargoyle, garguilo, gergel, gergely, gracile, graciously, grackle, graessle, grassel, grassley, gressley, grigoli, grisly, griswell, grizzell, grizzle, grizzly, grossly, grygiel, guariglia, gurgle