If you do it correctly, everytime you plug in the ATtiny85 board, it will appear as a Vendor-Specific Device with PID:0x0753 & VID:0x16d0. If you don't upload firmware, it will automatically become USBtinySPI with PID:0x0c9f & VID:0x1781 after 6 seconds.
After you confirm your bootloader is working, set fuse RSTDISBL with the ISP programmer.
Step 2, prepare dwire-debug
I did some improvement on dwire-debug and created a release here.
If you are using Mac, you can download binary, add execute permission with chmod +x dwdebug, install libusb with brew install libusb libusb-compat .
If you are using Windows, you need to use libusb-win32 driver for ATtiny85. Refer to Readme of dwire-debug repo for more info.
For other OS, try to compile the source in the release.
Step 3, reprogram fuse on ATmega328p
Connect all wires and USB cable. run the following command in terminal to read fuse. If the avrdude on your computer locates in a different location, change the path accordingly.