I was able to recoup half of the outright cash that my ex gave to the OW. The gifts, hotel stays, dinners out, and living la vida loca, I didn't get anything back from that (and that amount was much more than the cash gifts). But the cash which he transferred from his bank account to hers? I got half of it awarded back to me.
I had to show the bank records, though. Also, he was compelled on the witness stand to admit to this.