Earl makes some valid points. Personally I doubt that "wet" foam rinses any better or worse than a lighter foam. A lot depends on how your rinsing is set up as Earl suggests.
If that was happening the rinse was not that good.
A lot of times there is not adequate rinsing especially when under high pressure.
Thanks for all the advice. We apply foam then rinse then DA and final r/o. Most problems are from the aforementioned foam getting in cracks and blowers blowing it out.