When to use "Filterer" vs "Filter"? [closed]

I had suggested the following context in a comment under the question:

I am a filterer. It's my job to filter out bad information.

My thinking was filterer should distinguish itself from filter by designating somebody's role—rather than describing an object.

Although I realize that jars with the Collins definition of a thing, I thought I'd take a look at Merriam-Webster's definition of filterer—and I discovered something very interesting:

: a worker who tends a filtration process in any of various capacities (as by operating a filter press)

— called also filterman

Here is its definition of filterman:

1 : FILTERER
2 : DECKER MAN

And here is its definition of decker man:

: a paper-mill worker who operates a wet machine

— called also filterman

I should mention, however, that Lexico (Oxford) gives essentially the same definition as Collins:

Something which filters, or which acts as a filter.

Additionally, it provides no definition of either filterman or decker man.