I found myself in the same condition as you, I managed to solve it by creating a usb-stick using refus to write an .iso image downloaded from the eset site.
These are the options used:
Partition scheme: MBR
Target System: BIOS or Uefi
File system: FAT32
Cluster size: 4096
When asked DD or ISO I chose ISO.
The only problem is that you have to update the virus definitions with every use.
I hope I was helpful