The golden showers story outlined in the dossier alleged Trump found out he was sleeping in the same bed Obama slept in and called for prostitutes to pee on the bed. The story always sounded absurd. As it happened, it came up in the Mueller report in a footnote.
A Russian businessman involved in the Trump Tower Moscow project said that the tapes were fake, according to the Mueller report footnote. Here it is:
Comey’s briefing included the Steele reporting’s unverified allegation that the Russians had compromising tapes of the President involving conduct when he was a private citizen during a 2013 trip to Moscow for the Miss Universe Pageant. During the 2016 presidential campaign, a similar claim may have reached candidate Trump. On October 30, 2016, Michael Cohen received a text from Russian businessman Giorgi Rtskhiladze that said, “Stopped flow of tapes from Russia but not sure if there’s anything else. Just so you know… .” … Rtskhiladze said “tapes” referred to compromising tapes of Trump rumored to be held by persons associated with the Russian real estate conglomerate Crocus Group, which had helped host the 2013 Miss Universe Pageant in Russia. … Cohen said he spoke to Trump about the issue after receiving the texts from Rtskhiladze. … Rtskhiladze said he was told the tapes were fake, but he did not communicate that to Cohen.
There you have it, another source, a Russian says the dossier tale was fake.
The footnote arose from a conversation Trump had with Comey during the presidential transition about the dossier (the pee tape dossier).
The FBI used it to get a FISA warrant and three renewals to spy on the Trump campaign. They had to know it was a fake. They certainly knew it wasn’t verified. In the least, they didn’t try to find out before they used it to get a FISA warrant.