On the subject of brushes, i saw a video the other week advertsing a new smaller brush for fsg cleans, I ordered it, not cheap for what it is, and it came, god its small at only 5 inches but used it the other day and it was brilliant for the intricate cleaning of a fsg clean and also stupidly light which is handy when cleaning at some angles. the jets were also really powerful again which helped.
It was from cleanlynk and the brush is called a micro brush. Honestly, ive only used it once but it was brilliant.