Maybe not steel wool, then. Stainless steel scrubber pads wouldn’t rust and have an open enough “weave” to allow smaller water droplets to pass.
And yes, I’ve thought about a vacuum-adjustable valve on the bubbler line as well - but for now, as a proof of concept, I’d be ok with a fixed valve, knowing that the effect of the manifold vacuum would drop at higher throttle angles. An air pump on the air supply line to ensure bubbling continues regardless of throttle angle would make the most sense. But I’m also thinking about another discussion we had here: making the system a closed loop, with a cyclone separator mechanism that feeds condensate to a heated loop on the exhaust manifold, with steam rather than this water reservoir feeding into the intake. (Recycling condensed water vapour from blowby in the PCV system would be the most convenient, as it would be more continuous, regardless of throttle angle and intake vacuum. I could even insulate that from the colder weather, negating the need for alcohol in a reservoir to keep the water supply from freezing in winter. Plus, steam -according to everything I’ve seen in my research- is a better method for water injection due the the consistency as far as displacing air, but that would need to be metered/controlled by a valve as well to maintain quantity).
Sorry if I’m babbling - I’m tired from a day that started 19hrs ago. Let me know if I need to clarify...