Nick CW James BW ... cleaning is dangerous!!!! Lessons for us!
Nooooo!
Seriously though, judder isn't caused by washing your car (unless you never ever drive it and let the discs get so rusty with years of washing that the pads can't clean it off! However highly unlikely as cars get left for months outside with no issues).. it is usually caused by warped discs.
This can be a result of not bedding them in correctly or by prolonged excessive use without cooling and then applying the brakes in traffic whilst they are still boiling hot, the pads create a hot spot on the disc as it sits there with excess residual heat and this can cause them to warp.
This is why on track days you have cool down laps, and most cars are parked with their handbrakes off for a while in the pits afterwards to let the brakes cool.
