Countdown host Rachel Riley, 34, has opened up about her difficulties in trying to maintain her composure when “rude words” appear on the Channel 4 show’s board.The presenter admitted the programme’s producers and gallery are “just as filthy as you can imagine” and try to encourage a giggle from her during filming.While speaking exclusively to Express.co.uk about hosting Sky’s National General Knowledge Test with 100 quiz questions, Rachel revealed she often catches onto cheeky phrases, which sometimes go unnoticed by her co-stars Nick Hewer and Susie Dent.When quizzed on whether she finds it hard not to laugh when funny words are spelled out on the Countdown board, the star divulged: “All the time! “In my ear the producers and the gallery.