The Northern Irishman, who was called into Michael O'Neill's squad for the first time this month, cost the R's £2.8m in January, as reported by the Daily Mail, having scored 15 times for League One Peterborough United in all competitions.
Washington, though, endured a difficult start to the campaign, failing to score in any of his first nine league appearances, with his only goal before October coming in Posh's League Cup win against Crawley Town.
And the 23-year-old credits the advice he received from Graham Westley, who took over at London Road towards the end of his barren spell, for turning his season around.
"He used the analogy that your mum is locked up with a gun to her head in a room and the only way you can get her out is to win," Washington told the Times.
"How would that affect your performance? It struck a massive chord with me and a few other players. He said it was not the nicest thing to think of but use it if it gives you that edge and aggression."
Despite his international call, Washington has endured a similarly fruitless start to his QPR campaign, failing to find the net in any of his eight appearances so far.
As a result, the former postman has been left on the bench for the R's last three matches and is perhaps in need of a similarly emotive pep-talk from current boss Jimmy Floyd Hasselbaink.