Situation be very much different!  When everyone be work only with salary in own currency. Its easy.

Example. You want to hire a programmer. Buy on the exchange of its currency and then you will be able to hire him. Due to the fact that the exchange currency of the programmer will be in demand, for this reason, there will be a lot of exchangers that will be ready to change the currency of the programmer to the currency for which sellers will be ready to sell their goods. For the programmer and the seller it will be transparent. The programmer will pay his own currency. The seller will receive the one he would like to receive.

Exchangers will be part of the new institutional infrastructure that will take part of the credit business from banks. It is likely that some banks themselves will become members of this new Infrastructure