I'll answer this myself seeing as I found out roughly some more information but it seems as though this was the function of the 'Vestry Clerk' who under Parish Law was authorised and tasked with collecting the Church Rate.

I'm sure there was no set way to make collections it was likely collected upon entering the Church on Sundays, which in those days functioned more like a place to hear the weekly news and goings on in the Parish and the rest of the country.

But I'm sure at times the Vestry Clerk may have travelled house to house when significant arrears in Church Rates had accrued.