Over the years I've tried everything, including chroming (chrome's pretty slippery stuff) props to keep them free of fouling, all to no avail.
I've operated passenger vessels which run 6 or 7 days a week and the props still foul. Steel aloy, bronze; it makes no difference.
While making crossings on my circumnavigation, before electronic navigation, I used a taffrail log. This is a spinning propeller of sorts on a long line which gives pretty accurate distance and after days of dragging behind the boat all paint would be gone and the bronze would be shiny and polished, but the vessel's prop would be fouled. Go figure. Even if I was powering for days, the prop would foul, while the log's vane would not.
I wish you well with the Prop Glop; it would be fantastic if it works.