I got a real beauty just before Christmas. I had de-foamer in the waste tank, but as I went over an old coffee stain, the noise of the air made that hollow sound, if you catch my drift. I looked out and the Jag was toppers with foam and a huge white cloud appeared...
I ran to and switched the machine off, took the waste tank lid off and immediately ran the motors for 5 minutes.
I asked the lady if she had used Vanish and she said no, she'd used Fairy washing up liquid....