score:6
No, they do not accept any currency but US Dollars and Paraguayan Guarani. Further, the dollar bills must be in mint condition; all denominations were accepted (I paid with $100×1, $20×2, $5×3, and $1×5)
Luckily, there is an ATM in the room from which you can withdraw guarani upon arrival; I used this to account for my $100 bill being rejected due to a mark in the margin (see photo). Note that there may not be change in guarani or dollars.