usb - What is the quickest way to burn different ISO files to many flash drives?

I frequently have to burn many different ISO files to flash drives. Currently, I am using a program called ISO to USB to do this - but the issue is that it takes around 20 minutes per drive. I have to burn about 10 drives each day, each with different ISO files. What's the quickest way for me to do this?

Note: since I'm using separate ISO files, USB duplicators are not an option.

Thanks.