I had a nightmare with my foam lance, I'm at the point now where I'm trying to forget I ever wasted £50 on it.
Basically I got the lance from Autobrite along with 1L of Supa Snow foam, it went well and I enjoyed it, after I used up that litre I ordered 25L from AutoSmart, can't remember which of their foams it was. First few uses it was fine, then near the end of about my 4th ot 5th use of the AS foam it seemed to stop foaming, next time I used it the foam was useless watery and nothing like the shaving foam texture it used to have.
Autobrite told me to strip and clean it, I did this but didn't find find much dirt in it, they agreed to have it back, they cleaned it and sent it back, charging me £12, I tried it again but still the same, the flow seemed very restricted and the bit of foam was weak and watery. I returned it again and eventually got a new one, the new one worked fine for about 3 uses and then went the same way as my original one.
Is the foam solution some how damaging the lance?
I gave up long ago with it