Warnock berated the changing facilities on offer for his Middlesbrough side, who lost 1-0 at the bet365 Stadium courtesy of a first-half Nathan Collins header.
Covid rules mean visiting teams have to change in temporary accommodation to ensure social distancing.
But Warnock has said he will force Stoke into a portacabin that he would pay for out of his own pocket if necessary when they meet again at the Riverside on March 13.
He said: “It’s nice to get in here [the press room] where it’s quite warm. Those changing rooms were a pigsty. In fact, pigs would have seen it and run away.
“They stuck us in a little portacabin. Now you can’t tell me with social distancing we wouldn’t have been better off in the dressing room.
“We give them everything at Middlesbrough – heat, lovely room, and we’re in a pigsty around the corner here.
“The toilets don’t work, they’re blocked. We had fumes coming in before the game and we had to get the maintenance guy in. Why didn’t they look at that before we arrived?
“The showers were leaking, water everywhere on the floor. It’s an absolute disgrace.
“I didn’t say anything to the players before the game because you don’t want to make excuses, but it was an absolute disgrace today that.
“There’s no way we’re giving them a dressing room when they come up our place. If our chairman won’t, I’ll pay for a portacabin.”
Stoke move up to fifth with three points while Middlesbrough are 10th.
Warnock insisted his invective was not part of an excuse for the defeat.
He said: “You can’t blame it. I haven’t said anything to the players because I’m not about making excuses for the result.
“You just shouldn’t be made to change in a place like that. My dressing room was another portacabin 20 yards further down the road, water all over the floor and bloody freezing.
“We’ve taken pictures. It’s out of order. I know there’s a pandemic, but when you look at the facilities we give teams at Middlesbrough, I’m sure Stoke City from the Premier League can be better than that.”