The act of engaging in sexual intercourse with a grotty bitch, ie the sort of woman who leaves a snail-trail of cum where ever she goes as a direct result of her indiscriminate promiscuity. Leaving the "dipper" with the stigma of "dipping it in dirty water" and probably a venereal disease too.
"you slept with her!??!! I knew you had been Dipping it in Dirty water! she's a complete slut-bucket!!!"
Fogey/fogy /fougi/ sl. (early 18C+, orig. Scot) old-fashioned, stuck-in-the mud.
Person with old fashioned ideas which he is unwilling to change: Come to the disco and stop being such an old fogey!
You think me an old fogeyand an old tory, his thoughtful voice said. I saw three generations since O’Connel’s time. I remember the famine. Do you know that the orange lodges agitated for repeal of the union twenty years before O’Connel did or before the prelates of your communion denounced him as a demagogue? You fenians forget some things. (James Joyce, Ulysses. Penguin Books,1992. p. 38)