Sodade - Secaria Evora is a great example of avoiding consecutive 5ths

It is: 

C bE

C bE

D  F

D  F

bE  G

bE  G

D    F

D    F

and not

C  bE  G

C  bE  G

D   F   A

...

And if notes are sustained:

It sounds:

C  bE

C   bE

C    D    F

C     D    F

C     D     bE   G

C      D     bE    G

B      D      F     G

B     D     F     G

It is ingenious.

Here is what Bach says about consecutive fifths:

Please find General Bass Rules Bach PDF