Hiding the Price Paid at Trustee Sale

I was recording a trustee's deed in San Bernardino County yesterday and I was told by the clerk at the counter that I couldn't white-out the amount I paid at the trustee's sale. Usually when I record in Orange County if I file the "do not record" document along with the deed I am able to hide the price I paid. Anyone ever experienced this in San Bernardino? Why aren't the counties consistent - or was I wrongly advised by the clerk at the counter....?

Also - over the past couple of years I've noticed that even with filing the do not record and whiting out the price I paid, that the price still often ends up in MLS, Zillow, etc... Anyone have any thoughts on why this is?

Thanks!