I don't know too much about the swap trick since I have never attempted one successfully, but I can tell you that one reason as to why you couldn't get it done is because your discs are indeed of too low quality.
Originally Posted by Yo Yo Ma
Use Verbatim DVD-R discs (With Super AZO) that are manufactured by Mitsubishi or Taiyo Yuden. Avoid those made by CMC.
I used to have the same console model as you have, and it has a KHS-400C laser that refused to read any of my cheap discs that can be read by my SCPH-77006 console.
Unmodified SCPH-77006 with SM 3.6
SCPH-39006 with M-chip modchip, SCPH-10281 NA and refurb Seagate 80GB HDD
SCPH-10000 v1.00 with SCPH-10190 PCMCIA NA and SCPH-20400 HDD unit