Construct a 5x5 table and start filling
With no trial and error, 11 entries can be filled (bolded).
The remaining entries can be found by trial-and-error and/or exclusion principle.
Number: 1 2 3 4 5
Color: Y B R G W
Nat'l: N D B G S
Smoke: D B P P Bm
Pet: C H B F D
Drink: W T M C B
The German (house 4) has the fish.