Salt and pepper noise removal

Hi

I have a set of thermographic data in the form of pixel-pixel-time (third order tensor). At some point, I want to remove the salt and pepper noise from the data. So I am planning to a median filter, in particular I want to use the command

medfilt2

J = medfilt2(I,[m n]) performs median filtering, where each output pixel contains the median value in the m-by-n neighborhood around the corresponding pixel in the input image.

https://it.mathworks.com/help/images/ref/medfilt2.html

What could be standard criteria to define the size m and n?

I am working with black and white (grayscale) images (which are my thermal images).

From other analysis I know the size (in pixels) of an area where I could expect a possible defect. Maybe this sizes could become my m and n?

Greetings

Luca