Not my field, but whoever wrote this has done what I believe many Germans would do given the circumstances: use a compound noun to save space. “Calcofluor-Schleifmethode” seems to be short for “Methode zur Calcofluor-Färbung nach Herunterschleifen des Ausgangsmaterials.”

Earlier in the text that Justin provided, it says:
“Zur Beurteilung des Zellwandabbaus im Gerstenmalz sind weniger die Globalmethoden wie…als aussagefähig erkannt worden als vielmehr die spezifischen Untersuchungen des Zellwandabbaus mithilfe der Calcofluor-Methode.”
https://application.wiley-vch.de/books/sample/352734036X_c01...

The paragraph he quoted:
“…der die mehligen, halb- und ganzglasigen Körner erfasst, durch Färben des längs geteilten Korns (z. B. mittels Schleifen) mit Calcofluor oder Methylenblau, wodurch Auflösung und Homogenität derselben dargestellt werden.”

Obviously, “z.B.” means that “Schleifen” is just one way to do this. And, indeed, if you go looking for more sources describing the process, you’ll find:
“The major experimental techniques used have been light microscopy, scanning electron microscopy and 'sanded-block' staining methods in which either Calcofluor is used to locate ungraded cell walls, or dye penetration is used to locate modified regions.”

The authors then go on to explain:
“Sanded blocks. Two groups of 100 grains were from each micromalted sample. They were attached to plywood blocks with epoxide glue (Araldite Rapid) and were ground on belt sanding machine to expose the starchy endosperms at prechosen depth. After smoothing with fine sandpaper they were stained first with Calcofluor White M2R...and Fast Green FCF...and were photographed under ultraviolet light.”
https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416....

Similarly:
“According to the literature the most commonly used method to determine the homogeneity of malt relies on an examination of the non-friable fraction…A sample of malt is ground in a friabilimeter and the friability determined in the usual way…

“Another popular method of examining homogeneity is the use of dye staining of sectioned grains. Two dyes have been used methylene blue…and Calcofluor...The former relies on a non-specific penetration of modified endosperm by the blue dye. Grains are embedded into a resin matrix and are sectioned by sanding. They are then stained and dried and sanded once again…The Calcofluor method uses a similar procedure but, because the dye is specific for cell wall material, a second sanding is not required.”
https://projectblue.blob.core.windows.net/media/Default/Rese...

In other words, it seems as if “grinding” isn't inherently wrong. However, (a) sanding is more frequently used (I guess for the reason you pointed out in the d-box) and (b) I wouldn’t translate this literally because of how the author refers to the process—which kind of works in German (grammatically speaking, there’s no other way you can incorporate “-Schleif-” into the chosen compound) but I think looks a bit odd in English (as if Calcofluor were the name of the sanding method described or the only staining method used after sanding).

Even in German, I think you’d be more likely to see something like the following:
“Beispiel: Modifikation und Homogenität nach Carlsberg Calcofluor-Färbung”

Further:
“Malzkörner abgeschliffen vor der Calcofluorfärbung”
http://www.bmt-weigt.de/wp-content/uploads/2017/03/181214-Mä...

This is a PowerPoint slide, so space is of the essence too, but the steps taken are separated into their logical categories, as they do here in English:

“The assessment of modification using sanding and staining with Calcofluor, which is recommended by EBC…”
https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416....

Or:
“One of the ways of doing this is to sand 100 kernels that have been embedded in plastic, taking them down to about half their width and fully exposing the starchy endosperm. The plates are then flooded with Calcofluor…”
In: “Essays in Brewing Science,” by Michael J. Lewis and Charles W. Bamforth, published in 2006.

Also, the term “sanded” dates at least as far back as the 1970s:
“A third satisfactory, but more complex, technique is to stain the surfaces of cut or sanded seeds with Calcofluor White M2R New, then to counterstain with Fast Green FCF...”
In: “Brewing Science,” Vol. 3 (p. 465), edited by James Richard Allan Pollock, published in 1979.

I’m sure you can come up with something more succinct. But personally, I’d rip apart the compound (and definitely no hyphen!).