Non-Sterile product Test ( Microbial analysis)

As I know, during the microbial analysis (MLT) of non sterile product we perform both TAMC /TYMC ( pour plate method) and the pathogen tests .
But I have a doubt on this procedure .

So , when it’s comes to saline production ( IV fluid) what kind of a procedure, needs to follow since Dextrose Anhydrous is a solution ??

When it comes to membrane filtration method do we need to follow the procedure as WFI water testing or like product testing .
Eg :- in WIF testing we pour the sample directly in to the filtration units and rinse with 0.1% PB .

But my question is can we try the same procedure for the IV fluid ( non-sterile ) ?

Do we have to dilute the Dextrose Anhydrous solution sample ( non-sterile) in to SCDM ( 1:9) and then pour 100 ml in to the membrane filtration units .