There is a common minhag among Sefardim in particular to write Pitum Haktores on klaf and to read it as a segulah for wealth and other blessings. I just heard a shiur where a top notch Rov and posek rails against this and says that it is not correct because the gemara forbids one to write individual pesukim.
I am not a fan of saying that many good people are doing something wrong unless we are compelled to say so and there is no other recourse.
Here, there is a limmud zchus. See Tshuvos Vi-hanhagos 4/18 and Yabia Omer 9 page 306 ועוד ועוד ואין כאן מקום להאריך בזה!
