that they only use PIO for FETs, or as additional P4 supplementation when you're already on another form of vaginal P4 support. I don't believe they ever just give it as the solo P4 supp during the 2WW other than FET.
Totally know what you mean about that wet, greasy feeling. Since I was using both Crinone and P4 supps at the same time I didn't know which was the true culprit. And then once fully PG and the E2 was pumping away that discharge - oh boy, was just not a fun time down there at all. I prefered changing cotton undies frequently vs. using the liners.