My comment is legit, but obviously you don't know how it can happen legally. let me fill you in,also for any other interested persons.
To begin with, no Peruvian bank will open an account for a foreigner only on a passport....I tried many top banks here.
Scotiabank Peru advised me to use the Mirgraciones website and find the "PERMISO ESPECIAL PARA FIRMA CONTRATOS - PEFC section/link.
This advises that first you have to pay S/16.00 deposit into Banco de la Nacion, with your passport, so that they can register your name and passport number on the receipt.
Then return to the website and open that section again. Follow the instructions and enter your passport number and your name etc. It will accept that you have paid the S/ 16.00 and provide a printable document which gives your details on it, and also a second page with the Numero de Tramite and the word APROBADO (approved)...with a note that the permission is only valid for 30 days.
A bold font foot note says "additionally, a copy of the certificate has been sent to your e-mail address xxxxx (Check main tray or junk mail) ....print this also because it is the critical certificate that the bank requires to authorise you to open an account. IF you don't receive that email
...return to the website section again, enter your details and click on "consultar"and you certificate should appear. for printing. ( I know this becasue I did not receive the promised email and investugated a bit more....bingo !! )
Any other personal details required by the bank(of your choice) will be requested on the day you go in to that bank, with the Migraciones paperwork and certificate.
Why a person on a tourist visa would require permission to sign legal documents,or open a bank account, I will leave open. Mine was mandatory for my application for a Rentista visa.
So, senor(a) roadrunner...does that placate your doubts ??!! Hope so.
P.S I have read the link that you put..ummm I would not use BCP in a pink fit, mate !! For starters, their ATM's won't issue US dollars any more, plus the bank fees the other poster suffered.
Scotiabank Peru only charges 0.00001% or so, for received wire transfers. and has no other fees that I have experienced...plus it is an international bank (HQ in Canada, I think), so is can be handy in other countries also.
ATM's will issue both Soles and US dollars, in Peru's case.