> Surley any cleansing/removing of the filters would excite all the brain, as it reacts to new stimuli.

"Filter" in this case is just an analogy, and not necessarily a good one. We don't know the nature of consciousness and how it maps to brain activity, so it's not appropriate to assume that what is perceived as removing a "filter" is increasing stimuli, it's just processing it differently in some way.

I was replying to the someone, who it seems has misunderstood what Huxley meant by filters - I wasn't defending or affirming them, let alone discussing in what context they are 'appropriate'. I used the quote to give the 'filters' being discussed a context. Are you saying Huxley really meant: If the doors of perception were cleansed everything would not appear infinite but just 'processed differently'?