I used PETG with infill at 100% and it worked great. I actually printed two sets jjust in case, but the first one worked for both drains with noreal damage at all on the PETG dies. I used a ratchet and breaker bar to do the press.
Everyone else may already know this, but Sheetcam has the option to create shapes and one of them is a donut. So if you want to cut metal backing for the die you print it is easy. Just enter the diameter of the inner and outer circles and you have your piece. I discovered this after I did it the hard way.