Cleaning caravan with snow foam

I've used snow foam with a pressure washer on my caravan .... I just used a fairly cheap Car Plan foam/shampoo. I worked reasonably well, 👍

 ....  I worked reasonably well

Should have been ... IT worked reasonably well 🙄

Does snow foam remove those grey streaks?

no, not really. You still need Silky/etc for them

ive not used snow foam but have used the autoglym polar wash and then  polar seal applied with our worx power washer (low pressure washer) and the water beading is still present 6 weeks later..